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Probability-and-statistics/149898: This is an intro to probability chapter in a book called Applied mathmatics. The book is a combo of two diferent books especially made for my school.
This is the problem:
Find (2n+2)!/(2n)!
I know how to do algebra, my problem I believe is because of the ! symbol. I have just been introduced to it and understand the concept , but not how it works in an agebraic expression.
Itried soving for n but don't know what to do with the !
ineed to understand the steps involved.
this is the answer:
4n2 +6n + 2
thanks in advance for any help.
heidi

1 solutions

Answer 110003 by jim_thompson5910(28593) About Me  on 2008-07-27 13:24:04 (Show Source):
You can put this solution on YOUR website!
The notation n%21 tells you to simply multiply that number by every integer that is less than that number until you hit 1. So if n=5, this means that 5%21=5%285-1%29%2A%285-2%29%2A%285-3%29%2A%285-4%29=5%284%29%283%29%282%29%281%29=120.


In this case,




which simplifies to

and



So


Photobucket - Video and Image Hosting Highlight the common terms.


Photobucket - Video and Image Hosting Cancel out the common terms.


Simplify.


FOIL %282n%2B2%29%282n%2B1%29 to get 4n%5E2%2B4n%2B2n%2B2=4n%5E2%2B6n%2B2


Quadratic_Equations/149843: This question is from textbook
I don't know how to do this at all be if you can show me then it will help me do the other promblems. 5t^-10t=0
1 solutions

Answer 109970 by jim_thompson5910(28593) About Me  on 2008-07-26 22:13:14 (Show Source):
You can put this solution on YOUR website!

5t%5E2-10t=0 Start with the given equation


5t%28t-2%29=0 Factor the left side



Now set each factor equal to zero:
5t=0 or t-2=0

t=0 or t=2 Now solve for t in each case


So our answers are

t=0 or t=2


Polynomials-and-rational-expressions/149836: How do you factor xy - 3x - 8y + 24, whats the answer?
1 solutions

Answer 109964 by jim_thompson5910(28593) About Me  on 2008-07-26 21:00:18 (Show Source):
You can put this solution on YOUR website!
xy-3x-8y%2B24 Start with the given expression

%28xy-3x%29%2B%28-8y%2B24%29 Group like terms


x%28y-3%29-8%28y-3%29 Factor out the GCF x out of the first group. Factor out the GCF -8 out of the second group


%28x-8%29%28y-3%29 Since we have the common term y-3, we can combine like terms

So xy-3x-8y%2B24 factors to %28x-8%29%28y-3%29


Polynomials-and-rational-expressions/149833: How do you factor 4x%5E2+%2B+20x+%2B+5y+%2Bxy?
1 solutions

Answer 109961 by jim_thompson5910(28593) About Me  on 2008-07-26 20:48:39 (Show Source):
You can put this solution on YOUR website!
Well you can't solve it (since it's not an equation), but you can factor

4x%5E2%2B20x%2B5y%2Bxy Start with the given expression.


4x%5E2%2B20x%2Bxy%2B5y Rearrange the terms


%284x%5E2%2B20x%29%2B%28xy%2B5y%29 Group like terms


4x%28x%2B5%29%2By%28x%2B5%29 Factor out the GCF 4x out of the first group. Factor out the GCF y out of the second group


%284x%2By%29%28x%2B5%29 Since we have the common term x%2B5, we can combine like terms

So 4x%5E2%2B20x%2B5y%2Bxy factors to %284x%2By%29%28x%2B5%29


Graphs/149830: 2.) Compound interest. Suppose that $750 is invested at 7% interest, compounded semiannually.
A.) Find the function for the amount to which the investment grows after t years.
B.)Find the amount of money in the account at t=1, 6,10,15, and 25 yr

1 solutions

Answer 109956 by jim_thompson5910(28593) About Me  on 2008-07-26 19:52:58 (Show Source):
You can put this solution on YOUR website!
A)
The compound interest formula is A=P%281%2Br%2Fn%29%5E%28nt%29 where A is the return, P is the principal, r is the interest rate, n is the compound frequency, and t is the time in years.


So in this case, the principal is P=750, the rate is r=0.07 (note 7% is 0.07 in decimal form) and the compound frequency is n=2 (note: semiannually means that it is compounded twice a year)

So the equation is A=750%281%2B0.07%2F2%29%5E%282t%29

==============================================================================

B)

Let's find out how much money there is in the account after 1 year


A=750%281%2B0.07%2F2%29%5E%282%2At%29 Start with given equation


A=750%281%2B0.07%2F2%29%5E%282%2A1%29 Plug in t=1


A=750%281%2B0.035%29%5E%282%2A1%29 Divide 0.07 by 2 to get 0.035


A=750%281%2B0.035%29%5E%282%29 Multiply the exponents 2 and 1 to get 2


A=750%281.035%29%5E%282%29 Add 1 and 0.035 to get 1.035


A=750%281.071225%29 Raise 1.035 to the 2 th power to get 1.071225


A=803.41875 Multiply 750 and 1.071225 to get 803.41875


So in 1 year, there is $803.42 (rounded to the nearest cent) in the account

------------------------------------------------------------


Let's find out how much money there is in the account after 6 years


A=750%281%2B0.07%2F2%29%5E%282%2At%29 Start with given equation.


A=750%281%2B0.07%2F2%29%5E%282%2A6%29 Plug in t=6


A=750%281%2B0.035%29%5E%282%2A6%29 Divide 0.07 by 2 to get 0.035


A=750%281%2B0.035%29%5E%2812%29 Multiply the exponents 2 and 6 to get 12


A=750%281.035%29%5E%2812%29 Add 1 and 0.035 to get 1.035


A=750%281.51106865734636%29 Raise 1.035 to the 12 th power to get 1.51106865734636


A=1133.30149300977 Multiply 750 and 1.51106865734636 to get 1133.30149300977


So in 6 years, there is $1133.30 (rounded to the nearest cent) in the account



------------------------------------------------------------


Let's find out how much money there is in the account after 10 years


A=750%281%2B0.07%2F2%29%5E%282%2At%29 Start with given equation.


A=750%281%2B0.07%2F2%29%5E%282%2A10%29 Plug in t=10


A=750%281%2B0.035%29%5E%282%2A10%29 Divide 0.07 by 2 to get 0.035


A=750%281%2B0.035%29%5E%2820%29 Multiply the exponents 2 and 10 to get 20


A=750%281.035%29%5E%2820%29 Add 1 and 0.035 to get 1.035


A=750%281.98978886346584%29 Raise 1.035 to the 20 th power to get 1.98978886346584


A=1492.34164759938 Multiply 750 and 1.98978886346584 to get 1492.34164759938



So in 10 years, there is $1492.34 (rounded to the nearest cent) in the account

------------------------------------------------------------


Let's find out how much money there is in the account after 15 years


A=750%281%2B0.07%2F2%29%5E%282%2At%29 Start with given equation.


A=750%281%2B0.07%2F2%29%5E%282%2A15%29 Plug in t=15


A=750%281%2B0.035%29%5E%282%2A15%29 Divide 0.07 by 2 to get 0.035


A=750%281%2B0.035%29%5E%2830%29 Multiply the exponents 2 and 15 to get 30


A=750%281.035%29%5E%2830%29 Add 1 and 0.035 to get 1.035


A=750%282.80679370470263%29 Raise 1.035 to the 30 th power to get 2.80679370470263


A=2105.09527852697 Multiply 750 and 2.80679370470263 to get 2105.09527852697


So in 15 years, there is $2105.10 (rounded to the nearest cent) in the account

------------------------------------------------------------

Let's find out how much money there is in the account after 15 years


A=750%281%2B0.07%2F2%29%5E%282%2At%29 Start with given equation.


A=750%281%2B0.07%2F2%29%5E%282%2A25%29 Plug in t=25


A=750%281%2B0.035%29%5E%282%2A25%29 Divide 0.07 by 2 to get 0.035


A=750%281%2B0.035%29%5E%2850%29 Multiply the exponents 2 and 25 to get 50


A=750%281.035%29%5E%2850%29 Add 1 and 0.035 to get 1.035


A=750%285.58492685566332%29 Raise 1.035 to the 50 th power to get 5.58492685566332


A=4188.69514174749 Multiply 750 and 5.58492685566332 to get 4188.69514174749



So in 25 years, there is $4188.69 (rounded to the nearest cent) in the account



Graphs/149829: Solve the inequality x^2-x-6>0
1 solutions

Answer 109955 by jim_thompson5910(28593) About Me  on 2008-07-26 19:30:43 (Show Source):
You can put this solution on YOUR website!

x%5E2-x-6%3E0 Start with the given inequality


%28x%2B2%29%28x-3%29%3E0 Factor the left side


%28x%2B2%29%28x-3%29=0 Set the left side equal to zero


Set each individual factor equal to zero:

x%2B2=0 or x-3=0

Solve for x in each case:

x=-2 or x=3


So our critical values are x=-2 and x=3

Now set up a number line and plot the critical values on the number line

number_line%28+600%2C+-10%2C+10%2C-2%2C3%29



So let's pick some test points that are near the critical values and evaluate them.


Let's pick a test value that is less than -2 (notice how it's to the left of the leftmost endpoint):

So let's pick x=-3

x%5E2-x-6%3E0 Start with the given inequality


%28-3%2B2%29%28-3-3%29%3E+0 Plug in x=-3


6%3E+0 Evaluate and simplify the left side

Since the inequality is true, this means that the interval works. So this tells us that this interval is in our solution set.
So part our solution in interval notation is ()





---------------------------------------------------------------------------------------------



Let's pick a test value that is in between -2 and 3:

So let's pick x=0

x%5E2-x-6%3E0 Start with the given inequality


%280%2B2%29%280-3%29%3E+0 Plug in x=0


-6%3E+0 Evaluate and simplify the left side

Since the inequality is false, this means that the interval does not work. So this interval is not in our solution set and we can ignore it.


---------------------------------------------------------------------------------------------



Let's pick a test value that is greater than 3 (notice how it's to the right of the rightmost endpoint):

So let's pick x=4

x%5E2-x-6%3E0 Start with the given inequality


%284%2B2%29%284-3%29%3E+0 Plug in x=4


6%3E+0 Evaluate and simplify the left side

Since the inequality is true, this means that the interval works. So this tells us that this interval is in our solution set.
So part our solution in interval notation is ()





---------------------------------------------------------------------------------------------





Summary:

So the solution in interval notation is:


() ()





Here's a graph to visually verify the answer

+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+%28x%2B2%29%28x-3%29%29+


Exponents/149819: Find the exact area of a triangle with a base of sqrt of 30 meters and height sqrt of 6 meters.
1 solutions

Answer 109932 by jim_thompson5910(28593) About Me  on 2008-07-26 12:35:57 (Show Source):
You can put this solution on YOUR website!
A=%281%2F2%29b%2Ah Start with the area of a triangle formula



A=%281%2F2%29%28sqrt%2830%29%29%28sqrt%286%29%29 Plug in b=sqrt%2830%29 and h=sqrt%286%29


A=%28sqrt%28180%29%29%2F%282%29 Multiply


A=%286sqrt%285%29%29%2F%282%29 Simplify the square root.


A=3%2Asqrt%285%29 Reduce 6%2F2 to get 3%2F1 or just 3


So the area is A=3%2Asqrt%285%29


Radicals/149817: Is sqrt of a + sqrt of b = sqrt a+b for all values of a and b?
1 solutions

Answer 109929 by jim_thompson5910(28593) About Me  on 2008-07-26 12:33:03 (Show Source):
You can put this solution on YOUR website!
Let's assume that sqrt%28a%29%2Bsqrt%28b%29=sqrt%28a%2Bb%29 for all values of a and b. So now let's just pick arbitrary values for a and b. So let's make a=2 and b=3.


sqrt%28a%29%2Bsqrt%28b%29=sqrt%28a%2Bb%29 Start with the given equation.


sqrt%282%29%2Bsqrt%283%29=sqrt%282%2B3%29 Plug in a=2 and b=3


sqrt%282%29%2Bsqrt%283%29=sqrt%285%29 Add 2 and 3 to get 5


1.41421%2B1.73205=2.23607 Take the square root of 2 to get 1.41421. Take the square root of 3 to get 1.73205. Take the square root of 5 to get 2.23607.


3.14626=2.23607 Add 1.41421 and 1.73205 to get 3.14626


Since 3.14626%3C%3E2.23607, this shows us that sqrt%282%29%2Bsqrt%283%29%3C%3Esqrt%282%2B3%29.


So this means that sqrt%28a%29%2Bsqrt%28b%29%3C%3Esqrt%28a%2Bb%29. There are some values that will make it true. For instance a=0 and b=0 are one pair of values, a=1 and b=0 are another. However, in general, the equation sqrt%28a%29%2Bsqrt%28b%29=sqrt%28a%2Bb%29 is not true.


Exponents/149810: A 30 inch by 40 inch countertop for a work island is to be covered with green ceramic tiles, except for a border of uniform width, if the area covered by green tiles is 704 square inches (in^2 ) , then how wide is the border?
1 solutions

Answer 109925 by jim_thompson5910(28593) About Me  on 2008-07-26 12:21:38 (Show Source):
You can put this solution on YOUR website!
Let x=width of border.

First, let's draw the picture.

Photobucket - Video and Image Hosting

note: the lengths 40-2x and 30-2x are due to the subtraction of 2 "x" lengths. Take note that there are two dashed lines per side that are not part of the green tiles.


From the picture, we see that the actual counter top is 40-2x by 30-2x. So the length is L=40-2x and the width is W=30-2x


Now remember, the area of a rectangle is

A=L%2AW

704=%2840-2x%29%2830-2x%29 Plug in the given area of the green tiles A=704, L=40-2x and W=30-2x


704=1200-140x%2B4x%5E2 FOIL


0=1200-140x%2B4x%5E2-704 Subtract 704 from both sides.


0=4x%5E2-140x%2B496 Combine like terms.


Let's use the quadratic formula to solve for x


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%28-140%29+%2B-+sqrt%28+%28-140%29%5E2-4%284%29%28496%29+%29%29%2F%282%284%29%29 Plug in a=4, b=-140, and c=496


x+=+%28140+%2B-+sqrt%28+%28-140%29%5E2-4%284%29%28496%29+%29%29%2F%282%284%29%29 Negate -140 to get 140.


x+=+%28140+%2B-+sqrt%28+19600-4%284%29%28496%29+%29%29%2F%282%284%29%29 Square -140 to get 19600.


x+=+%28140+%2B-+sqrt%28+19600-7936+%29%29%2F%282%284%29%29 Multiply 4%284%29%28496%29 to get 7936


x+=+%28140+%2B-+sqrt%28+11664+%29%29%2F%282%284%29%29 Subtract 7936 from 19600 to get 11664


x+=+%28140+%2B-+sqrt%28+11664+%29%29%2F%288%29 Multiply 2 and 4 to get 8.


x+=+%28140+%2B-+108%29%2F%288%29 Take the square root of 11664 to get 108.


x+=+%28140+%2B+108%29%2F%288%29 or x+=+%28140+-+108%29%2F%288%29 Break up the expression.


x+=+%28248%29%2F%288%29 or x+=++%2832%29%2F%288%29 Combine like terms.


x+=+31 or x+=+4 Simplify.


So the possible answers are x+=+31 or x+=+4


However, we need to see if they generate reasonable lengths and widths


Let's check the solution x+=+31


L=40-2x Go back to the length equation


L=40-2%2831%29 Plug in x+=+31


L=40-62 Multiply


L=-22 Subtract


Since a negative length is not possible, this means that the value x+=+31 is a reasonable solution.


----------------------------



Let's check the solution x+=+4


L=40-2x Go back to the length equation


L=40-2%284%29 Plug in x+=+4


L=40-8 Multiply


L=32 Subtract

So we get a reasonable length with x+=+4

--------

W=30-2x Go back to the width equation


W=30-2%284%29 Plug in x+=+4


W=30-8 Multiply


W=22 Subtract

So we also get a reasonable width with x+=+4


===============================================

Answer:

So the only solution is x+=+4


So the width of the border is 4 inches


Polynomials-and-rational-expressions/149802: 1. Use synthetic division to divide the polynomial 2x^3 + 7x^2 – 5 by 3+x and write the quotient and the remainder
2. Consider the polynomial f(x)= 4x^4+5x^3 + 7x^2 – 34x+8
By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.


Find all of the zeros of the given polynomial. Show procedure

1 solutions

Answer 109921 by jim_thompson5910(28593) About Me  on 2008-07-26 11:37:26 (Show Source):
You can put this solution on YOUR website!
# 1

Let's simplify this expression using synthetic division


Start with the given expression %282x%5E3+%2B+7x%5E2+-+5%29%2F%283%2Bx%29

First lets find our test zero:

3%2Bx=0 Set the denominator 3%2Bx equal to zero

x=-3 Solve for x.

so our test zero is -3


Now set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the numerator to the right of the test zero.(note: remember if a polynomial goes from 7x%5E2 to -5x%5E0 there is a zero coefficient for x%5E1. This is simply because 2x%5E3+%2B+7x%5E2+-+5 really looks like 2x%5E3%2B7x%5E2%2B0x%5E1%2B-5x%5E0
-3|270-5
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 2)
-3|270-5
|
2

Multiply -3 by 2 and place the product (which is -6) right underneath the second coefficient (which is 7)
-3|270-5
|-6
2

Add -6 and 7 to get 1. Place the sum right underneath -6.
-3|270-5
|-6
21

Multiply -3 by 1 and place the product (which is -3) right underneath the third coefficient (which is 0)
-3|270-5
|-6-3
21

Add -3 and 0 to get -3. Place the sum right underneath -3.
-3|270-5
|-6-3
21-3

Multiply -3 by -3 and place the product (which is 9) right underneath the fourth coefficient (which is -5)
-3|270-5
|-6-39
21-3

Add 9 and -5 to get 4. Place the sum right underneath 9.
-3|270-5
|-6-39
21-34


Since the last column adds to 4, we have a remainder of 4. This means 3%2Bx is not a factor of 2x%5E3+%2B+7x%5E2+-+5

Now lets look at the bottom row of coefficients:


The first 3 coefficients (2,1,-3) form the quotient

2x%5E2+%2B+x+-+3

and the last coefficient 4, is the remainder, which is placed over 3%2Bx like this

4%2F%283%2Bx%29



Putting this altogether, we get:

2x%5E2+%2B+x+-+3%2B4%2F%283%2Bx%29

So %282x%5E3+%2B+7x%5E2+-+5%29%2F%283%2Bx%29=2x%5E2+%2B+x+-+3%2B4%2F%283%2Bx%29

which looks like this in remainder form:
%282x%5E3+%2B+7x%5E2+-+5%29%2F%283%2Bx%29=2x%5E2+%2B+x+-+3 remainder 4



-----------------------------------
Answer:

So the quotient is 2x%5E2+%2B+x+-+3 and the remainder is 4




# 2


a)


Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 8 (the last coefficient):



Now let's list the factors of 4 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur










b)


Now let's use synthetic division to test each possible zero:




Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 1%2F2:
1/2|457-348
| 27/221/4-115/8
4721/2-115/4-51/8

Since the remainder -51%2F8 (the right most entry in the last row) is not equal to zero, this means that 1%2F2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 1%2F4:
1/4|457-348
| 13/217/8-255/32
4617/2-255/81/32

Since the remainder 1%2F32 (the right most entry in the last row) is not equal to zero, this means that 1%2F4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 2:
2|457-348
| 8266664
413333272

Since the remainder 72 (the right most entry in the last row) is not equal to zero, this means that 2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 4:
4|457-348
| 16843641320
421913301328

Since the remainder 1328 (the right most entry in the last row) is not equal to zero, this means that 4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 8:
8|457-348
| 32296242419120
437303239019128

Since the remainder 19128 (the right most entry in the last row) is not equal to zero, this means that 8 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1:
-1|457-348
| -4-1-640
416-4048

Since the remainder 48 (the right most entry in the last row) is not equal to zero, this means that -1 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1%2F2:
-1/2|457-348
| -2-3/2-11/4147/8
4311/2-147/4211/8

Since the remainder 211%2F8 (the right most entry in the last row) is not equal to zero, this means that -1%2F2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1%2F4:
-1/4|457-348
| -1-1-3/271/8
446-71/2135/8

Since the remainder 135%2F8 (the right most entry in the last row) is not equal to zero, this means that -1%2F4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -2:
-2|457-348
| -86-26120
4-313-60128

Since the remainder 128 (the right most entry in the last row) is not equal to zero, this means that -2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -4:
-4|457-348
| -1644-204952
4-1151-238960

Since the remainder 960 (the right most entry in the last row) is not equal to zero, this means that -4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -8:
-8|457-348
| -32216-178414544
4-27223-181814552

Since the remainder 14552 (the right most entry in the last row) is not equal to zero, this means that -8 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8



====================================

Since none of the possible rational roots are actual roots, this means that the polynomial either has irrational roots or complex roots.




Trigonometry-basics/149789: find the exact value of tan(-3 pie)
1 solutions

Answer 109891 by jim_thompson5910(28593) About Me  on 2008-07-25 21:26:47 (Show Source):
You can put this solution on YOUR website!
tan%28-3pi%29


-tan%283pi%29 Use the identity tan%28-u%29=-tan%28u%29 to rewrite the expression.


-sin%283pi%29%2Fcos%283pi%29 Rewrite tangent in terms of sine and cosine.


-sin%282pi%2Bpi%29%2Fcos%282pi%2Bpi%29 Rewrite 3pi as 2pi%2Bpi


Rewrite the expression using the identities sin%28A%2BB%29=sin%28A%29cos%28B%29%2Bcos%28A%29sin%28B%29 and cos%28A%2BB%29=cos%28A%29cos%28B%29-sin%28A%29sin%28B%29


Now, let's reference the unit circle




From the unit circle, we can see that at the angle pi, there is a point on the unit circle . So this tells us that cos%28pi%29=-1 and sin%28pi%29=0. Also at the angle 2pi, there is a point on the unit circle . So this tells us that cos%282pi%29=1 and sin%282pi%29=0.

-%28%280%29%28-1%29%2B%281%29%280%29%29%2F%28%281%29%28-1%29-%280%29%280%29%29 Take the cosine of pi to get -1. Take the sine of pi to get 0. Take the cosine of 2pi to get 1. Take the sine of 2pi to get 0.


-%280%2B0%29%2F%28-1%2B0%29 Multiply


-%280%29%2F%28-1%29 Add


0 Reduce


So tan%28-3pi%29=0


Polynomials-and-rational-expressions/149769: don't know how to check my amswers for these....
simplify: (3x^3-x^2-4x+1)/(x-1)
factor: 18x+x^2-11x
factor: 6x^2+x-2
factor: 12x^3+31x^2+20x
1 solutions

Answer 109869 by jim_thompson5910(28593) About Me  on 2008-07-25 17:08:18 (Show Source):
You can put this solution on YOUR website!
# 1


Let's simplify this expression using synthetic division


Start with the given expression %283x%5E3+-+x%5E2+-+4x+%2B+1%29%2F%28x-1%29

First lets find our test zero:

x-1=0 Set the denominator x-1 equal to zero

x=1 Solve for x.

so our test zero is 1


Now set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the numerator to the right of the test zero.
1|3-1-41
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 3)
1|3-1-41
|
3

Multiply 1 by 3 and place the product (which is 3) right underneath the second coefficient (which is -1)
1|3-1-41
|3
3

Add 3 and -1 to get 2. Place the sum right underneath 3.
1|3-1-41
|3
32

Multiply 1 by 2 and place the product (which is 2) right underneath the third coefficient (which is -4)
1|3-1-41
|32
32

Add 2 and -4 to get -2. Place the sum right underneath 2.
1|3-1-41
|32
32-2

Multiply 1 by -2 and place the product (which is -2) right underneath the fourth coefficient (which is 1)
1|3-1-41
|32-2
32-2

Add -2 and 1 to get -1. Place the sum right underneath -2.
1|3-1-41
|32-2
32-2-1


Since the last column adds to -1, we have a remainder of -1. This means x-1 is not a factor of 3x%5E3+-+x%5E2+-+4x+%2B+1
Now lets look at the bottom row of coefficients:

The first 3 coefficients (3,2,-2) form the quotient

3x%5E2+%2B+2x+-+2

and the last coefficient -1, is the remainder, which is placed over x-1 like this

-1%2F%28x-1%29



Putting this altogether, we get:

3x%5E2+%2B+2x+-+2%2B-1%2F%28x-1%29

So %283x%5E3+-+x%5E2+-+4x+%2B+1%29%2F%28x-1%29=3x%5E2+%2B+2x+-+2%2B-1%2F%28x-1%29







18x%2Bx%5E2-11x Start with the given expression.


x%5E2%2B7x Combine like terms.


x%28x%2B7%29 Factor out the GCF x



------------------------------------------------------------

Answer:
So 18x%2Bx%5E2-11x factors to x%28x%2B7%29







# 3



Looking at 6x%5E2%2Bx-2 we can see that the first term is 6x%5E2 and the last term is -2 where the coefficients are 6 and -2 respectively.

Now multiply the first coefficient 6 and the last coefficient -2 to get -12. Now what two numbers multiply to -12 and add to the middle coefficient 1? Let's list all of the factors of -12:



Factors of -12:
1,2,3,4,6,12

-1,-2,-3,-4,-6,-12 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to -12
(1)*(-12)
(2)*(-6)
(3)*(-4)
(-1)*(12)
(-2)*(6)
(-3)*(4)

note: remember, the product of a negative and a positive number is a negative number


Now which of these pairs add to 1? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 1

First NumberSecond NumberSum
1-121+(-12)=-11
2-62+(-6)=-4
3-43+(-4)=-1
-112-1+12=11
-26-2+6=4
-34-3+4=1



From this list we can see that -3 and 4 add up to 1 and multiply to -12


Now looking at the expression 6x%5E2%2Bx-2, replace x with -3x%2B4x (notice -3x%2B4x adds up to x. So it is equivalent to x)

6x%5E2%2Bhighlight%28-3x%2B4x%29%2B-2


Now let's factor 6x%5E2-3x%2B4x-2 by grouping:


%286x%5E2-3x%29%2B%284x-2%29 Group like terms


3x%282x-1%29%2B2%282x-1%29 Factor out the GCF of 3x out of the first group. Factor out the GCF of 2 out of the second group


%283x%2B2%29%282x-1%29 Since we have a common term of 2x-1, we can combine like terms

So 6x%5E2-3x%2B4x-2 factors to %283x%2B2%29%282x-1%29


So this also means that 6x%5E2%2Bx-2 factors to %283x%2B2%29%282x-1%29 (since 6x%5E2%2Bx-2 is equivalent to 6x%5E2-3x%2B4x-2)



------------------------------------------------------------



Answer:
So 6x%5E2%2Bx-2 factors to %283x%2B2%29%282x-1%29





# 4



12x%5E3%2B31x%5E2%2B20x Start with the given expression


x%2812x%5E2%2B31x%2B20%29 Factor out the GCF x


Now let's focus on the inner expression 12x%5E2%2B31x%2B20




------------------------------------------------------------



Looking at 12x%5E2%2B31x%2B20 we can see that the first term is 12x%5E2 and the last term is 20 where the coefficients are 12 and 20 respectively.

Now multiply the first coefficient 12 and the last coefficient 20 to get 240. Now what two numbers multiply to 240 and add to the middle coefficient 31? Let's list all of the factors of 240:



Factors of 240:
1,2,3,4,5,6,8,10,12,15,16,20,24,30,40,48,60,80,120,240

-1,-2,-3,-4,-5,-6,-8,-10,-12,-15,-16,-20,-24,-30,-40,-48,-60,-80,-120,-240 ...List the negative factors as well. This will allow us to find all possible combinations

These factors pair up and multiply to 240
1*240
2*120
3*80
4*60
5*48
6*40
8*30
10*24
12*20
15*16
(-1)*(-240)
(-2)*(-120)
(-3)*(-80)
(-4)*(-60)
(-5)*(-48)
(-6)*(-40)
(-8)*(-30)
(-10)*(-24)
(-12)*(-20)
(-15)*(-16)

note: remember two negative numbers multiplied together make a positive number


Now which of these pairs add to 31? Lets make a table of all of the pairs of factors we multiplied and see which two numbers add to 31

First NumberSecond NumberSum
12401+240=241
21202+120=122
3803+80=83
4604+60=64
5485+48=53
6406+40=46
8308+30=38
102410+24=34
122012+20=32
151615+16=31
-1-240-1+(-240)=-241
-2-120-2+(-120)=-122
-3-80-3+(-80)=-83
-4-60-4+(-60)=-64
-5-48-5+(-48)=-53
-6-40-6+(-40)=-46
-8-30-8+(-30)=-38
-10-24-10+(-24)=-34
-12-20-12+(-20)=-32
-15-16-15+(-16)=-31



From this list we can see that 15 and 16 add up to 31 and multiply to 240


Now looking at the expression 12x%5E2%2B31x%2B20, replace 31x with 15x%2B16x (notice 15x%2B16x adds up to 31x. So it is equivalent to 31x)

12x%5E2%2Bhighlight%2815x%2B16x%29%2B20


Now let's factor 12x%5E2%2B15x%2B16x%2B20 by grouping:


%2812x%5E2%2B15x%29%2B%2816x%2B20%29 Group like terms


3x%284x%2B5%29%2B4%284x%2B5%29 Factor out the GCF of 3x out of the first group. Factor out the GCF of 4 out of the second group


%283x%2B4%29%284x%2B5%29 Since we have a common term of 4x%2B5, we can combine like terms

So 12x%5E2%2B15x%2B16x%2B20 factors to %283x%2B4%29%284x%2B5%29


So this also means that 12x%5E2%2B31x%2B20 factors to %283x%2B4%29%284x%2B5%29 (since 12x%5E2%2B31x%2B20 is equivalent to 12x%5E2%2B15x%2B16x%2B20)



------------------------------------------------------------




So our expression goes from x%2812x%5E2%2B31x%2B20%29 and factors further to x%283x%2B4%29%284x%2B5%29


------------------
Answer:

So 12x%5E3%2B31x%5E2%2B20x factors to x%283x%2B4%29%284x%2B5%29


Rational-functions/149768: Graph the polynomial function P%28x%29=x%5E4%2Bx%5E3-3x%5E2-5x-2 to approximately find the function's zeros, then use synthetic division and the remainder theorem to exactly find its zeros.
1 solutions

Answer 109867 by jim_thompson5910(28593) About Me  on 2008-07-25 16:37:14 (Show Source):
You can put this solution on YOUR website!
First, let's graph the function P%28x%29=x%5E4%2Bx%5E3-3x%5E2-5x-2 to get



From the graph, we can see that the graph has the approximate zeros x=-1 and x=2

==============================================================

Now let's use the Rational Root Theorem to list all of the possible rational roots

Rational Root Theorem:

where p and q are the factors of the last and first coefficients


So let's list the factors of -2 (the last coefficient):



Now let's list the factors of 1 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient





Now simplify

These are all the distinct rational zeros of the function that could occur




---------------------------------------------


Now let's use synthetic division to test each possible zero




Let's see if the possible zero 1 is really a root for the function x%5E4%2Bx%5E3-3x%5E2-5x-2


So let's make the synthetic division table for the function x%5E4%2Bx%5E3-3x%5E2-5x-2 given the possible zero 1:
1|11-3-5-2
| 12-1-6
12-1-6-8

Since the remainder -8 (the right most entry in the last row) is not equal to zero, this means that 1 is not a zero of x%5E4%2Bx%5E3-3x%5E2-5x-2


------------------------------------------------------


Let's see if the possible zero 2 is really a root for the function x%5E4%2Bx%5E3-3x%5E2-5x-2


So let's make the synthetic division table for the function x%5E4%2Bx%5E3-3x%5E2-5x-2 given the possible zero 2:
2|11-3-5-2
| 2662
13310

Since the remainder 0 (the right most entry in the last row) is equal to zero, this means that 2 is a zero of x%5E4%2Bx%5E3-3x%5E2-5x-2


------------------------------------------------------


Let's see if the possible zero -1 is really a root for the function x%5E4%2Bx%5E3-3x%5E2-5x-2


So let's make the synthetic division table for the function x%5E4%2Bx%5E3-3x%5E2-5x-2 given the possible zero -1:
-1|11-3-5-2
| -1032
10-3-20

Since the remainder 0 (the right most entry in the last row) is equal to zero, this means that -1 is a zero of x%5E4%2Bx%5E3-3x%5E2-5x-2


------------------------------------------------------


Let's see if the possible zero -2 is really a root for the function x%5E4%2Bx%5E3-3x%5E2-5x-2


So let's make the synthetic division table for the function x%5E4%2Bx%5E3-3x%5E2-5x-2 given the possible zero -2:
-2|11-3-5-2
| -2226
1-1-1-34

Since the remainder 4 (the right most entry in the last row) is not equal to zero, this means that -2 is not a zero of x%5E4%2Bx%5E3-3x%5E2-5x-2



===========================================
Summary:

So only -1 and 2 are actually rational roots.


Now looking back at the table for the test zero -1, we see
-1|11-3-5-2
| -1032
10-3-20


The bottom row of coefficients (minus the last one) form the quotient
x%5E3-3x-2



Now let's perform synthetic division using the other zero 2 on the function x%5E3-3x-2



2|10-3-2
| 242
1210

Since the remainder 0 (the right most entry in the last row) is equal to zero, this means that 2 is a zero of x%5E3-3x-2

Once again the first three coefficients in the bottom row form the quotient

x%5E2%2B2x%2B1


Let's use the quadratic formula to find the zeros of x%5E2%2B2x%2B1


x+=+%28-b+%2B-+sqrt%28+b%5E2-4ac+%29%29%2F%282a%29 Start with the quadratic formula


x+=+%28-%282%29+%2B-+sqrt%28+%282%29%5E2-4%281%29%281%29+%29%29%2F%282%281%29%29 Plug in a=1, b=2, and c=1


x+=+%28-2+%2B-+sqrt%28+4-4%281%29%281%29+%29%29%2F%282%281%29%29 Square 2 to get 4.


x+=+%28-2+%2B-+sqrt%28+4-4+%29%29%2F%282%281%29%29 Multiply 4%281%29%281%29 to get 4


x+=+%28-2+%2B-+sqrt%28+0+%29%29%2F%282%281%29%29 Subtract 4 from 4 to get 0


x+=+%28-2+%2B-+sqrt%28+0+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-2+%2B-+0%29%2F%282%29 Take the square root of 0 to get 0.


x+=+%28-2+%2B+0%29%2F%282%29 or x+=+%28-2+-+0%29%2F%282%29 Break up the expression.


x+=+%28-2%29%2F%282%29 or x+=++%28-2%29%2F%282%29 Combine like terms.


x+=+-1 or x+=+-1 Simplify.


So the zeros of x%5E2%2B2x%2B1 are x+=+-1 or x+=+-1 or just x+=+-1 with a multiplicity of 2


Now there are 3 instances where we get a zero of x+=+-1. So this tells us that the zero x+=+-1 has a multiplicity of 3

================================================

Answer:

So the zeros of P%28x%29=x%5E4%2Bx%5E3-3x%5E2-5x-2 are -1 (with a multiplicity of 3) and x=2


Rational-functions/149767: What is the remainder when x%5E7-x%5E6%2Bx%5E5-x%5E4%2B4 is divided by x-1
1 solutions

Answer 109866 by jim_thompson5910(28593) About Me  on 2008-07-25 16:18:09 (Show Source):
You can put this solution on YOUR website!
Let's simplify this expression using synthetic division


Start with the given expression %28x%5E7+-+x%5E6+%2B+x%5E5+-+x%5E4+%2B+4%29%2F%28x-1%29

First lets find our test zero:

x-1=0 Set the denominator x-1 equal to zero

x=1 Solve for x.

so our test zero is 1


Now set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the numerator to the right of the test zero.(note: remember if a polynomial goes from -x%5E4 to 4 there is a zero coefficient for x%5E3, x%5E2, and x. This is simply because x%5E7+-+x%5E6+%2B+x%5E5+-+x%5E4+%2B+4 really looks like 1x%5E7%2B-1x%5E6%2B1x%5E5%2B-1x%5E4%2B0x%5E3%2B0x%5E2%2B0x%5E1%2B4x%5E0
1|1-11-10004
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)
1|1-11-10004
|
1

Multiply 1 by 1 and place the product (which is 1) right underneath the second coefficient (which is -1)
1|1-11-10004
|1
1

Add 1 and -1 to get 0. Place the sum right underneath 1.
1|1-11-10004
|1
10

Multiply 1 by 0 and place the product (which is 0) right underneath the third coefficient (which is 1)
1|1-11-10004
|10
10

Add 0 and 1 to get 1. Place the sum right underneath 0.
1|1-11-10004
|10
101

Multiply 1 by 1 and place the product (which is 1) right underneath the fourth coefficient (which is -1)
1|1-11-10004
|101
101

Add 1 and -1 to get 0. Place the sum right underneath 1.
1|1-11-10004
|101
1010

Multiply 1 by 0 and place the product (which is 0) right underneath the fifth coefficient (which is 0)
1|1-11-10004
|1010
1010

Add 0 and 0 to get 0. Place the sum right underneath 0.
1|1-11-10004
|1010
10100

Multiply 1 by 0 and place the product (which is 0) right underneath the sixth coefficient (which is 0)
1|1-11-10004
|10100
10100

Add 0 and 0 to get 0. Place the sum right underneath 0.
1|1-11-10004
|10100
101000

Multiply 1 by 0 and place the product (which is 0) right underneath the seventh coefficient (which is 0)
1|1-11-10004
|101000
101000

Add 0 and 0 to get 0. Place the sum right underneath 0.
1|1-11-10004
|101000
1010000

Multiply 1 by 0 and place the product (which is 0) right underneath the eighth coefficient (which is 4)
1|1-11-10004
|1010000
1010000

Add 0 and 4 to get 4. Place the sum right underneath 0.
1|1-11-10004
|1010000
10100004



Since the last column adds to 4, we have a remainder of 4.


--------------------------------------------

Answer:

So when x%5E7-x%5E6%2Bx%5E5-x%5E4%2B4 is divided by x-1, the remainder is 4


Rational-functions/149766: Find the quotient of x%5E5%2B32 divided by x%2B2
1 solutions

Answer 109865 by jim_thompson5910(28593) About Me  on 2008-07-25 16:12:43 (Show Source):
You can put this solution on YOUR website!
Let's simplify this expression using synthetic division


Start with the given expression %28x%5E5+%2B+32%29%2F%28x%2B2%29

First lets find our test zero:

x%2B2=0 Set the denominator x%2B2 equal to zero

x=-2 Solve for x.

so our test zero is -2


Now set up the synthetic division table by placing the test zero in the upper left corner and placing the coefficients of the numerator to the right of the test zero.(note: remember if a polynomial goes from x%5E5 to 32 there is a zero coefficient for x%5E4, x%5E3, x%5E2, and x. This is simply because x%5E5+%2B+32 really looks like 1x%5E5%2B0x%5E4%2B0x%5E3%2B0x%5E2%2B0x%5E1%2B32x%5E0
-2|1000032
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 1)
-2|1000032
|
1

Multiply -2 by 1 and place the product (which is -2) right underneath the second coefficient (which is 0)
-2|1000032
|-2
1

Add -2 and 0 to get -2. Place the sum right underneath -2.
-2|1000032
|-2
1-2

Multiply -2 by -2 and place the product (which is 4) right underneath the third coefficient (which is 0)
-2|1000032
|-24
1-2

Add 4 and 0 to get 4. Place the sum right underneath 4.
-2|1000032
|-24
1-24

Multiply -2 by 4 and place the product (which is -8) right underneath the fourth coefficient (which is 0)
-2|1000032
|-24-8
1-24

Add -8 and 0 to get -8. Place the sum right underneath -8.
-2|1000032
|-24-8
1-24-8

Multiply -2 by -8 and place the product (which is 16) right underneath the fifth coefficient (which is 0)
-2|1000032
|-24-816
1-24-8

Add 16 and 0 to get 16. Place the sum right underneath 16.
-2|1000032
|-24-816
1-24-816

Multiply -2 by 16 and place the product (which is -32) right underneath the sixth coefficient (which is 32)
-2|1000032
|-24-816-32
1-24-816

Add -32 and 32 to get 0. Place the sum right underneath -32.
-2|1000032
|-24-816-32
1-24-8160


Since the last column adds to zero, we have a remainder of zero. This means x%2B2 is a factor of x%5E5+%2B+32

Now lets look at the bottom row of coefficients:

The first 5 coefficients (1,-2,4,-8,16) form the quotient

x%5E4+-+2x%5E3+%2B+4x%5E2+-+8x+%2B+16


------------------------------------------------
Answer:

So %28x%5E5+%2B+32%29%2F%28x%2B2%29=x%5E4+-+2x%5E3+%2B+4x%5E2+-+8x+%2B+16 which means that the quotient is x%5E4+-+2x%5E3+%2B+4x%5E2+-+8x+%2B+16 and the remainder is 0.


Rational-functions/149765: Use the Intermediate Value Theorem to determine if P%28x%29=2x%5E5-7x%2B1 has a zero in the interval [1,2]
1 solutions

Answer 109864 by jim_thompson5910(28593) About Me  on 2008-07-25 16:09:18 (Show Source):
You can put this solution on YOUR website!
To use the intermediate value theorem, simply evaluate the endpoints of the interval.


Let's evaluate the left endpoint x=1


P%28x%29=2x%5E5-7x%2B1 Start with the given equation.


P%281%29=2%281%29%5E5-7%281%29%2B1 Plug in x=1.


P%281%29=2%281%29-7%281%29%2B1 Raise 1 to the 5th power to get 1.


P%281%29=2-7%281%29%2B1 Multiply 2 and 1 to get 2.


P%281%29=2-7%2B1 Multiply -7 and 1 to get -7.


P%281%29=-4 Combine like terms.


So the function value at x=1 is P%281%29=-4. This makes the point (1,-4) which tells us that the y-coordinate is negative.

--------------------------------------

Now let's evaluate the right endpoint x=2


P%28x%29=2x%5E5-7x%2B1 Start with the given equation.


P%282%29=2%282%29%5E5-7%282%29%2B1 Plug in x=2.


P%282%29=2%2832%29-7%282%29%2B1 Raise 2 to the 5th power to get 32.


P%282%29=64-7%282%29%2B1 Multiply 2 and 32 to get 64.


P%282%29=64-14%2B1 Multiply -7 and 2 to get -14.


P%282%29=51 Combine like terms.



So the function value at x=2 is P%282%29=51. This makes the point (2,51) which tells us that the y-coordinate is positive.



Since the sign of the y-coordinate transitioned from negative to positive on the interval [1,2], this means that the graph must have crossed the x-axis somewhere in the interval. So there is a zero in the interval [1,2].


Rational-functions/149763: Find the zeros of x%5E3-x%5E2-2x%2B2 and the multiplicity of each.
1 solutions

Answer 109863 by jim_thompson5910(28593) About Me  on 2008-07-25 16:05:48 (Show Source):
You can put this solution on YOUR website!
First, let's list all of the possible rational zeros.

Any rational zero can be found through this formula

where p and q are the factors of the last and first coefficients


So let's list the factors of 2 (the last coefficient):



Now let's list the factors of 1 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient






Now simplify

These are all the distinct rational zeros of the function that could occur




------------------------


Now let's test each possible rational root with use of synthetic division




Let's see if the possible zero 1 is really a root for the function x%5E3-x%5E2-2x%2B2


So let's make the synthetic division table for the function x%5E3-x%5E2-2x%2B2 given the possible zero 1:
1|1-1-22
| 10-2
10-20

Since the remainder 0 (the right most entry in the last row) is equal to zero, this means that 1 is a zero of x%5E3-x%5E2-2x%2B2


------------------------------------------------------


Let's see if the possible zero 2 is really a root for the function x%5E3-x%5E2-2x%2B2


So let's make the synthetic division table for the function x%5E3-x%5E2-2x%2B2 given the possible zero 2:
2|1-1-22
| 220
1102

Since the remainder 2 (the right most entry in the last row) is not equal to zero, this means that 2 is not a zero of x%5E3-x%5E2-2x%2B2


------------------------------------------------------


Let's see if the possible zero -1 is really a root for the function x%5E3-x%5E2-2x%2B2


So let's make the synthetic division table for the function x%5E3-x%5E2-2x%2B2 given the possible zero -1:
-1|1-1-22
| -120
1-202

Since the remainder 2 (the right most entry in the last row) is not equal to zero, this means that -1 is not a zero of x%5E3-x%5E2-2x%2B2


------------------------------------------------------


Let's see if the possible zero -2 is really a root for the function x%5E3-x%5E2-2x%2B2


So let's make the synthetic division table for the function x%5E3-x%5E2-2x%2B2 given the possible zero -2:
-2|1-1-22
| -26-8
1-34-6

Since the remainder -6 (the right most entry in the last row) is not equal to zero, this means that -2 is not a zero of x%5E3-x%5E2-2x%2B2



===========================================

So to recap, we only found one rational zero. So the only rational zero for the function x%5E3-x%5E2-2x%2B2 is 1

Now if we go back to the corresponding synthetic division table for the test zero 1, we get

1|1-1-22
| 10-2
10-20


Now looking at the bottom row of coefficients, we see the first three numbers: 1, 0 and -2

These coefficients form the quotient x%5E2%2B0x-2 or just x%5E2-2

This means that %28x%5E3-x%5E2-2x%2B2%29%2F%28x-1%29=x%5E2-2 or x%5E3-x%5E2-2x%2B2=%28x-1%29%28x%5E2-2%29

x%5E2-2=0 Set the quotient equal to zero


x%5E2=2 Add 2 to both sides.


x=0%2B-sqrt%282%29 Take the square root of both sides.


x=sqrt%282%29 or x=-sqrt%282%29 Break up the expression.


So the remaining two zeros are x=sqrt%282%29 or x=-sqrt%282%29


===============================================

Answer:

So the zeros of x%5E3-x%5E2-2x%2B2 are:

1, x=sqrt%282%29 or x=-sqrt%282%29 where each zero has a multiplicity of 1.


Miscellaneous_Word_Problems/149757: A wooden fence surrounds a garden that is in the shape of an irregular triangle. If one side is twice as long as the first, and another is half as long as the first side, and the fence is 70 feet long, what are the dimensions of the garden?
( Make a drawing, assign a variable, answer the question asked, check your work)
Thank you very much.
1 solutions

Answer 109862 by jim_thompson5910(28593) About Me  on 2008-07-25 15:33:06 (Show Source):
You can put this solution on YOUR website!
Let x=length of first side.


Since "one side is twice as long as the first", this means that y=2x


Also, because "another is half as long as the first side", this means that z=%281%2F2%29x



However, there's a problem. In order for any triangle to be constructed, the lengths of any two sides must be greater than the length of the third side. So for instance, this means that x%2Bz%3Ey.

x%2B%281%2F2%29x%3E2x Plug in y=2x and z=%281%2F2%29x


%283%2F2%29x%3E2x Add


Since this inequality is never true for any positive x values, this means that you cannot construct a triangle with sides of x, 2x, and %281%2F2%29x (go ahead and try it out on paper if you don't believe me).


So I would double check the problem.


Trigonometry-basics/149721: Find the exact value of cot(-pie/6)
1 solutions

Answer 109860 by jim_thompson5910(28593) About Me  on 2008-07-25 15:21:18 (Show Source):
You can put this solution on YOUR website!
cot%28-pi%2F6%29 Start with the given expression.


1%2Ftan%28-pi%2F6%29 Rewrite the cotangent in terms of tangent.


1%2F%28-tan%28pi%2F6%29%29 Use the identity tan%28-u%29=-tan%28u%29 to rewrite the expression.


-1%2Ftan%28pi%2F6%29 Reduce.


-1%2F%28%28sin%28pi%2F6%29%29%2F%28cos%28pi%2F6%29%29%29 Rewrite the tangent function in terms of sine and cosine.


-1%28cos%28pi%2F6%29%2Fsin%28pi%2F6%29%29 Multiply -1 by the reciprocal of the dividing fraction.


-cos%28pi%2F6%29%2Fsin%28pi%2F6%29 Multiply.



Now, let's reference the unit circle




From the unit circle, we can see that at the angle pi%2F6, there is a point on the unit circle . So this tells us that cos%28pi%2F6%29=sqrt%283%29%2F2 and sin%28pi%2F6%29=1%2F2



So this means that -cos%28pi%2F6%29%2Fsin%28pi%2F6%29 then becomes -%28sqrt%283%29%2F2%29%2F%281%2F2%29


-%28sqrt%283%29%2F2%29%2A%282%2F1%29 Multiply the first fraction by the reciprocal of the second fraction.


-%28sqrt%283%29%2Fcross%282%29%29%2A%28cross%282%29%2F1%29 Cancel like terms.


-sqrt%283%29 Multiply and simplify.


So cot%28-pi%2F6%29=-sqrt%283%29


Polynomials-and-rational-expressions/149748: This question is from textbook Elementary and Intermediate Algebra
-2x – 8
x²+ 2x-8

1 solutions

Answer 109858 by jim_thompson5910(28593) About Me  on 2008-07-25 15:08:45 (Show Source):
You can put this solution on YOUR website!

%28-2x-8%29%2F%28x%5E2%2B2x-8%29 Start with the given expression.


%28-2%28x%2B4%29%29%2F%28x%5E2%2B2x-8%29 Factor -2x-8 to get -2%28x%2B4%29.


%28-2%28x%2B4%29%29%2F%28%28x%2B4%29%2A%28x-2%29%29 Factor x%5E2%2B2x-8 to get %28x%2B4%29%2A%28x-2%29.


%28-2highlight%28%28x%2B4%29%29%29%2F%28highlight%28%28x%2B4%29%29%28x-2%29%29 Highlight the common terms.


%28-2cross%28%28x%2B4%29%29%29%2F%28cross%28%28x%2B4%29%29%28x-2%29%29 Cancel out the common terms.


%28-2%29%2F%28x-2%29 Simplify.


So %28-2x-8%29%2F%28x%5E2%2B2x-8%29 simplifies to %28-2%29%2F%28x-2%29.


In other words, %28-2x-8%29%2F%28x%5E2%2B2x-8%29=%28-2%29%2F%28x-2%29 where x%3C%3E-4 or x%3C%3E2


Polynomials-and-rational-expressions/149749: This question is from textbook Elementary and Intermediate Algebra
Perform the indicated operation
-2a² 20a
3a² ˚ 15a³

1 solutions

Answer 109857 by jim_thompson5910(28593) About Me  on 2008-07-25 15:05:05 (Show Source):
You can put this solution on YOUR website!
%28%28-2a%5E2%29%2F%283a%5E2%29%29%28%2820a%29%2F%2815a%5E3%29%29 Start with the given expression.


%28%28-2a%5E2%29%2820a%29%29%2F%28%283a%5E2%29%2815a%5E3%29%29 Combine the fractions.


%28-40a%5E3%29%2F%2845a%5E5%29 Multiply.


%28-2%2A2%2A2%2A5%2Aa%2Aa%2Aa%29%2F%283%2A3%2A5%2Aa%2Aa%2Aa%2Aa%2Aa%29 Expand. Remember, -40a%5E3=-2%2A2%2A2%2A5%2Aa%2Aa%2Aa and 45a%5E5=3%2A3%2A5%2Aa%2Aa%2Aa%2Aa%2Aa


Highlight the common terms.


Cancel out the common terms.


%28-2%2A2%2A2%29%2F%283%2A3%2Aa%2Aa%29 Simplify.


%28-8%29%2F%289%2Aa%5E2%29 Regroup.


So %28%28-2a%5E2%29%2F%283a%5E2%29%29%28%2820a%29%2F%2815a%5E3%29%29 simplifies to %28-8%29%2F%289%2Aa%5E2%29.


In other words, %28%28-2a%5E2%29%2F%283a%5E2%29%29%28%2820a%29%2F%2815a%5E3%29%29=%28-8%29%2F%289%2Aa%5E2%29 where a%3C%3E0


Square-cubic-other-roots/149754: 3rd time lucky maybe
I need some help on one of my questions. I need to make g the subject...
T = 2(pi)*[square root of (l/g^3)}
Can someone please help me......: and its the letter L not the number 1
1 solutions

Answer 109856 by jim_thompson5910(28593) About Me  on 2008-07-25 14:59:24 (Show Source):
You can put this solution on YOUR website!
T+=+2pi%2Asqrt%28L%2Fg%5E3%29+ Start with the given equation.


T%2F%282pi%29+=+sqrt%28L%2Fg%5E3%29+ Divide both sides by 2pi.


%28T%2F%282pi%29%29%5E2+=+L%2Fg%5E3+ Square both sides. This will eliminate the square root.


g%5E3%28T%2F%282pi%29%29%5E2+=+L Multiply both sides by g%5E3.


g%5E3%28T%5E2%2F%282pi%29%5E2%29+=+L+ Distribute the outer exponent.


g%5E3%28T%5E2%2F%284pi%5E2%29%29+=+L+ Square 2pi to get %282pi%29%5E2=%282pi%29%282pi%29=4pi%5E2.


g%5E3%28T%5E2%29+=+L%284pi%5E2%29+ Multiply both sides by 4pi%5E2.


g%5E3+=+L%284pi%5E2%29%2F%28T%5E2%29+ Divide both sides by T%5E2.


g+=+root%283%2CL%284pi%5E2%29%2F%28T%5E2%29%29+ Take the cube root of both sides.


logarithm/149752: log r - log t + 2 log s
1 solutions

Answer 109855 by jim_thompson5910(28593) About Me  on 2008-07-25 14:53:08 (Show Source):
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log%2810%2C%28r%29%29-log%2810%2C%28t%29%29%2B2log%2810%2C%28s%29%29 Start with the given expression.


log%2810%2C%28r%29%29-log%2810%2C%28t%29%29%2Blog%2810%2C%28s%5E2%29%29 Rewrite 2log%2810%2C%28s%29%29 as log%2810%2C%28s%5E2%29%29 using the identity y%2Alog%28b%2C%28x%29%29=log%28b%2C%28x%5Ey%29%29


log%2810%2C%28r%2Ft%29%29%2Blog%2810%2C%28s%5E2%29%29 Combine the logs using the identity log%28b%2C%28A%29%29-log%28b%2C%28B%29%29=log%28b%2C%28A%2FB%29%29


log%2810%2C%28%28r%2Ft%29%28s%5E2%29%29%29 Combine the logs using the identity log%28b%2C%28A%29%29%2Blog%28b%2C%28B%29%29=log%28b%2C%28A%2AB%29%29


log%2810%2C%28rs%5E2%2Ft%29%29%29 Simplify.


So log%2810%2C%28r%29%29-log%2810%2C%28t%29%29%2B2log%2810%2C%28s%29%29 simplifies to log%2810%2C%28rs%5E2%2Ft%29%29%29


logarithm/149753: log x + log 2 = 5
1 solutions

Answer 109853 by jim_thompson5910(28593) About Me  on 2008-07-25 14:45:30 (Show Source):
You can put this solution on YOUR website!
log%2810%2C%28x%29%29%2Blog%2810%2C%282%29%29=5 Start with the given equation.


log%2810%2C%282x%29%29=5 Combine the logs using the identity log%28b%2C%28A%29%29%2Blog%28b%2C%28B%29%29=log%28b%2C%28A%2AB%29%29


10%5E5=2x Rewrite the equation using the property: log%28b%2C%28x%29%29=y ====> b%5Ey=x


100000=2x Raise 10 to the 5th power to get 100,000


50000=x Divide both sides by 2.


So the answer is x=50000


Graphs/149741: 1. Given the polynomial f(x) = 4x^4 + 5x^3 + 7x^2 - 34x + 8

(a) By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.








(b) Find all of the zeros of the given polynomial. Show the procedure





1 solutions

Answer 109852 by jim_thompson5910(28593) About Me  on 2008-07-25 14:32:40 (Show Source):
You can put this solution on YOUR website!
a)


Any rational zero can be found through this equation

where p and q are the factors of the last and first coefficients


So let's list the factors of 8 (the last coefficient):



Now let's list the factors of 4 (the first coefficient):



Now let's divide each factor of the last coefficient by each factor of the first coefficient









Now simplify

These are all the distinct rational zeros of the function that could occur










b)


Now let's use synthetic division to test each possible zero:




Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 1%2F2:
1/2|457-348
| 27/221/4-115/8
4721/2-115/4-51/8

Since the remainder -51%2F8 (the right most entry in the last row) is not equal to zero, this means that 1%2F2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 1%2F4:
1/4|457-348
| 13/217/8-255/32
4617/2-255/81/32

Since the remainder 1%2F32 (the right most entry in the last row) is not equal to zero, this means that 1%2F4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 2:
2|457-348
| 8266664
413333272

Since the remainder 72 (the right most entry in the last row) is not equal to zero, this means that 2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 4:
4|457-348
| 16843641320
421913301328

Since the remainder 1328 (the right most entry in the last row) is not equal to zero, this means that 4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero 8:
8|457-348
| 32296242419120
437303239019128

Since the remainder 19128 (the right most entry in the last row) is not equal to zero, this means that 8 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1:
-1|457-348
| -4-1-640
416-4048

Since the remainder 48 (the right most entry in the last row) is not equal to zero, this means that -1 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1%2F2:
-1/2|457-348
| -2-3/2-11/4147/8
4311/2-147/4211/8

Since the remainder 211%2F8 (the right most entry in the last row) is not equal to zero, this means that -1%2F2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -1%2F4:
-1/4|457-348
| -1-1-3/271/8
446-71/2135/8

Since the remainder 135%2F8 (the right most entry in the last row) is not equal to zero, this means that -1%2F4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -2:
-2|457-348
| -86-26120
4-313-60128

Since the remainder 128 (the right most entry in the last row) is not equal to zero, this means that -2 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -4:
-4|457-348
| -1644-204952
4-1151-238960

Since the remainder 960 (the right most entry in the last row) is not equal to zero, this means that -4 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8


------------------------------------------------------


Let's make the synthetic division table for the function 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8 given the possible zero -8:
-8|457-348
| -32216-178414544
4-27223-181814552

Since the remainder 14552 (the right most entry in the last row) is not equal to zero, this means that -8 is not a zero of 4x%5E4%2B5x%5E3%2B7x%5E2-34x%2B8



====================================

Since none of the possible rational roots are actual roots, this means that the polynomial either has irrational roots or complex roots.


Inequalities/149690: -2x-4<10
I think i need to get rid of the -4 first.
-2x-4<10
-2x+4<10+4
-2x+4<14
not sure where to go from here, nor am i sure this is right
1 solutions

Answer 109820 by jim_thompson5910(28593) About Me  on 2008-07-25 01:03:14 (Show Source):
You can put this solution on YOUR website!

-2x-4%3C10 Start with the given inequality.


-2x%3C10%2B4 Add 4 to both sides.


-2x%3C14 Combine like terms on the right side.


x%3E%2814%29%2F%28-2%29 Divide both sides by -2 to isolate x. note: Remember, the inequality sign flips when we divide both sides by a negative number.


x%3E-7 Reduce.


----------------------------------------------------------------------

Answer:

So the answer is x%3E-7


So the answer in interval notation is


Also, the answer in set-builder notation is



Here's the graph of the solution set




Expressions-with-variables/149691: 3x + 4y = 8 for y
1 solutions

Answer 109819 by jim_thompson5910(28593) About Me  on 2008-07-25 01:01:29 (Show Source):
You can put this solution on YOUR website!

3x+%2B+4y+=+8 Start with the given equation.


4y=8-3x Subtract 3x from both sides.


4y=-3x%2B8 Rearrange the terms.


y=%28-3x%2B8%29%2F%284%29 Divide both sides by 4 to isolate y.


y=-%283%2F4%29x%2B2 Break up the fraction and simplify.


Inequalities/149694: This question is from textbook
Thank you in advance for helping me with writing this problem in interval notation. The absolute value of 2x+1>=3 I have( -infintiy, -2]U[1,infinity ) Am I close?
1 solutions

Answer 109818 by jim_thompson5910(28593) About Me  on 2008-07-25 00:59:50 (Show Source):
You can put this solution on YOUR website!

abs%282x%2B1%29%3E=3 Start with the given inequality


Break up the absolute value (remember, if you have abs%28x%29%3E=+a, then x+%3C=+-a or x+%3E=+a)

2x%2B1+%3C=+-3 or 2x%2B1+%3E=+3 Break up the absolute value inequality using the given rule




Now lets focus on the first inequality 2x%2B1+%3C=+-3


2x%2B1%3C=-3 Start with the given inequality


2x%3C=-3-1Subtract 1 from both sides


2x%3C=-4 Combine like terms on the right side


x%3C=%28-4%29%2F%282%29 Divide both sides by 2 to isolate x



x%3C=-2 Divide


Now lets focus on the second inequality 2x%2B1+%3E=+3


2x%2B1%3E=3 Start with the given inequality


2x%3E=3-1Subtract 1 from both sides


2x%3E=2 Combine like terms on the right side


x%3E=%282%29%2F%282%29 Divide both sides by 2 to isolate x



x%3E=1 Divide



----------------------------------------------------

Answer:

So our answer is

x+%3C=+-2 or x+%3E=+1



So the solution in interval notation is: (] [)




Here's the graph of the solution set




Note:
There is a closed circle at x=-2 which means that we're including that value from the solution set.


Also, there is a closed circle at x=1 which means that we're including that value from the solution set.


Equations/149693: This question is from textbook
Thank you in advance for helping me with writing this problem in interval notation. The absolute value of 5x-3=10
1 solutions

Answer 109817 by jim_thompson5910(28593) About Me  on 2008-07-25 00:56:55 (Show Source):
You can put this solution on YOUR website!

abs%285x-3%29=10 Start with the given equation


Break up the absolute value (remember, if you have abs%28x%29=a, then x=-a or x=a)

5x-3=-10 or 5x-3=10 Set the expression 5x-3 equal to the original value 10 and it's opposite -10




Now lets focus on the first equation 5x-3=-10


5x=-10%2B3Add 3 to both sides


5x=-7 Combine like terms on the right side


x=%28-7%29%2F%285%29 Divide both sides by 5 to isolate x



x=-7%2F5 Reduce







Now lets focus on the second equation 5x-3=10



5x=10%2B3Add 3 to both sides


5x=13 Combine like terms on the right side


x=%2813%29%2F%285%29 Divide both sides by 5 to isolate x



x=13%2F5 Reduce





So the solutions to abs%285x-3%29=10 are:

x=-7%2F5 and x=13%2F5


Inequalities/149696: How do you write an inequality using x
Example:i have at least $25 in my pocket
1 solutions

Answer 109816 by jim_thompson5910(28593) About Me  on 2008-07-25 00:55:05 (Show Source):
You can put this solution on YOUR website!
Let x=amount of money in your pocket.


So when you have "at least $25", this means that you have 25 or more. Mathematically speaking, this means that some unknown quantity "x" is greater than or equal to 25.


So symbolically, this inequality is


Inequalities/149695: This question is from textbook
Thank you in advance for helping me with writing this problem in interval notation. The absolute value of 5n-2<2 I have 01 solutions

Answer 109815 by jim_thompson5910(28593) About Me  on 2008-07-25 00:52:33 (Show Source):
You can put this solution on YOUR website!

abs%285n-2%29%3C2 Start with the given inequality


Break up the absolute value (remember, if you have abs%28x%29%3C+a, then x+%3E+-a and x+%3C+a)

5n-2+%3E+-2 and 5n-2+%3C+2 Break up the absolute value inequality using the given rule


-2+%3C+5n-2+%3C+2 Combine the two inequalities to get a compound inequality



0+%3C+5n+%3C+4 Add 2 to all sides


0+%3C+n+%3C+4%2F5 Divide all sides by 5 to isolate n



----------------------------------------------------

Answer:

So our answer is

0+%3C+n+%3C+4%2F5



which looks like this in interval notation