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Graphs/148407: (-2,4) (0,-4) (2.4,-2.6176) Form an equation from these plotted points and answer these questions below:
Is the degree of the polynomial odd or even?
Is the leading coefficient of the polynomial positive or negative?
Number of zeros?

1 solutions

Answer 108760 by jim_thompson5910(28598) About Me  on 2008-07-15 18:08:20 (Show Source):
You can put this solution on YOUR website!
# 26

First let's plot the points

Photobucket - Video and Image Hosting


Now let's draw a quadratic through these points (let me know if any other type of polynomial needs to be drawn otherwise)

Photobucket - Video and Image Hosting



If you need the equation of the quadratic, simply set up the system of equations


system%284a-2b%2Bc=4%2C5.76a%2B2.4b%2Bc=-2.6176%2Cc=-4%29

note: let me know if you need help with the setup

Now use either your graphing calculator or other software to solve for "a","b", and "c" simultaneously through the use of matrices. The solution that I get is

a = 1.04, b = -1.92 and c = -4

So the equation that goes through these points is y=1.04x%5E2-1.92x-4


Is the degree of the polynomial odd or even?
Notice how as x approaches negative infinity (ie x goes to the left), then y approaches infinity. Also as x approaches positive infinity (ie x goes to the right), then y approaches infinity. So this tells us that the degree of the polynomial is even. Also, from the equation y=1.04x%5E2-1.92x-4, we can see that the degree is 2, which is even.


Is the leading coefficient of the polynomial positive or negative?

Since the parabola is opening upward, this means that the leading coefficient is positive. Also, since the leading coefficient is 1.04, this also tells us that the leading coefficient is positive.



Number of zeros?
From the graph, we can see that there are two zeros. Also, if you use the quadratic equation on y=1.04x%5E2-1.92x-4, you'll find that the polynomial has 2 zeros.


Graphs/148406: (-1,2) (0,0)(1,-2) Form an equation from these plots and answer the same questions above:
Is the degree of the polynomial odd or even?
Is the leading coefficient of the polynomial positive or negative?
Number of zeros?

1 solutions

Answer 108759 by jim_thompson5910(28598) About Me  on 2008-07-15 18:07:15 (Show Source):
You can put this solution on YOUR website!
If we plot the points we get

Photobucket - Video and Image Hosting

Now draw a curve through these points to get the equation:

Photobucket - Video and Image Hosting


Now if we find the equation of the line through those points, we get the equation y=-2x

note: let me know if you need help with finding the equation of the line.

Is the degree of the polynomial odd or even?
The degree is odd since one end of the polynomial goes in the positive y direction and the other end goes in the negative y direction.


Is the leading coefficient of the polynomial positive or negative?
Since the leading coefficient is -2, this means that the leading coefficient is negative.

Number of zeros?
From the graph, we can see that there is only one zero


Graphs/148405: 24. From the list of plotted points

(-5,5) (3,5)
(-4, 3/2) (2, 3/2)
(-3,-1) (1,-1)
(-2, -5/2) (0, -5/2)
(-1,-3)
Form an equation after plotting these points and then answer the questions below:
Is the degree of the polynomial odd or even?
Is the leading coefficient of the polynomial positive or negative?
Number of zeros

1 solutions

Answer 108758 by jim_thompson5910(28598) About Me  on 2008-07-15 18:05:43 (Show Source):
You can put this solution on YOUR website!
If we plot the points we get

Photobucket - Video and Image Hosting

Now draw a curve through these points to get the equation:

Photobucket - Video and Image Hosting

From the graph, we can see that the degree is even (since both ends of the graph go in the same y direction). Also, we can see that the leading coefficient is positive (since the graph opens upward). Finally, we can see that there are two zeros (since there are two x-intercepts).

------------------------------------------------------
Since we have all of this info, we don't need the equation. However, if you do need the equation, this is how you would find it:

From the graph, we can see that the vertex is (-1,-3).


y=a%28x-h%29%5E2%2Bk Start with the general vertex equation.


y=a%28x--1%29%5E2-3 Plug in h=-1 and k=-3


y=a%28x%2B1%29%5E2-3 Simplify.

Now let's plug in another point. Let's plug in (1,-1)

-1=a%281%2B1%29%5E2-3 Plug in x=1 and y=-1


-1=a%282%29%5E2-3 Add


-1=4a-3 Square 2 to get 4.


0=4a-3%2B1 Add 1 to both sides.


-4a=-3%2B1 Subtract 4a from both sides.


-4a=-2 Combine like terms on the right side.


a=%28-2%29%2F%28-4%29 Divide both sides by -4 to isolate a.


a=1%2F2 Reduce.

So this means that the equation is y=%281%2F2%29%28x%2B1%29%5E2-3

y=%281%2F2%29%28x%5E2%2B2x%2B1%29-3 FOIL


y=%281%2F2%29x%5E2%2B%281%2F2%292x%2B%281%2F2%291-3 Distribute


y=%281%2F2%29x%5E2%2Bx%2B1%2F2-3 Multiply


y=%281%2F2%29x%5E2%2Bx-5%2F2 Combine like terms.


So the equation that goes through the points is y=%281%2F2%29x%5E2%2Bx-5%2F2

From the equation, we can see that the degree of the polynomial is even. Also, we can see that the leading coefficient is positive since a=1%2F2. Finally, if we use the quadratic formula, we'll find that the polynomial y=%281%2F2%29x%5E2%2Bx-5%2F2 has 2 zeros.



Equations/148310: 3x + 4 = 4x -5
3x +4-4= 4x-5-4
3x=4x-1
3x=4x-1
3 = 3
3x=3x
3 =3
x=3
I know i'm doing somthing wrong. I think i miss a step.

1 solutions

Answer 108709 by jim_thompson5910(28598) About Me  on 2008-07-15 00:15:47 (Show Source):
You can put this solution on YOUR website!

3x%2B4=4x-5 Start with the given equation.


3x=4x-5-4 Subtract 4 from both sides.


3x-4x=-5-4 Subtract 4x from both sides.


-x=-5-4 Combine like terms on the left side.


-x=-9 Combine like terms on the right side.


x=%28-9%29%2F%28-1%29 Divide both sides by -1 to isolate x.


x=9 Reduce.


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

Answer:

So the answer is x=9


Rational-functions/148309: Write in standard form: (3-3i)/(4i)
1 solutions

Answer 108708 by jim_thompson5910(28598) About Me  on 2008-07-15 00:09:24 (Show Source):
You can put this solution on YOUR website!

%283-3i%29%2F%284i%29 Start with the given expression.


%28%283-3i%29%2F%284i%29%29%28i%2Fi%29 Multiply the fraction by i%2Fi


%28%283-3i%29i%29%2F%28%284i%29i%29 Combine the fractions


%283i-3i%5E2%29%2F%284i%5E2%29 Distribute and multiply


%283i-3%28-1%29%29%2F%284%28-1%29%29 Replace i%5E2 with -1


%283i%2B3%29%2F%28-4%29 Multiply


%283i%29%2F%28-4%29%2B%283%29%2F%28-4%29 Break up the fraction


-%283%2F4%29i-3%2F4 Reduce


-3%2F4-%283%2F4%29i Rearrange the terms.



Now the number is in standard form a+bi where a=-3%2F4 and b=-3%2F4


Rational-functions/148308: Write in standard form: -i+(7+5i)-3(2-3i)
1 solutions

Answer 108707 by jim_thompson5910(28598) About Me  on 2008-07-15 00:07:53 (Show Source):
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-i%2B%287%2B5i%29-3%282-3i%29 Start with the given expression.


-i%2B7%2B5i-6%2B9i%29 Distribute


%287-6%29%2B%28-i%2B5i%2B9i%29 Group like terms


1%2B13i Group like terms

Now the number is in standard form a+bi where a=1 and b=13


Rational-functions/148307: Write in standard form: (3-2i)^2
1 solutions

Answer 108706 by jim_thompson5910(28598) About Me  on 2008-07-14 23:59:23 (Show Source):
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%283-2i%29%5E2 Start with the given expression.


%283-2i%29%283-2i%29 Expand. Remember something like x%5E2=x%2Ax.


Now let's FOIL the expression.


Remember, when you FOIL an expression, you follow this procedure:


%28highlight%283%29-2i%29%28highlight%283%29-2i%29 Multiply the First terms:%283%29%2A%283%29=9.


%28highlight%283%29-2i%29%283%2Bhighlight%28-2i%29%29 Multiply the Outer terms:%283%29%2A%28-2%2Ai%29=-6%2Ai.


%283%2Bhighlight%28-2i%29%29%28highlight%283%29-2i%29 Multiply the Inner terms:%28-2%2Ai%29%2A%283%29=-6%2Ai.


%283%2Bhighlight%28-2i%29%29%283%2Bhighlight%28-2i%29%29 Multiply the Last terms:%28-2%2Ai%29%2A%28-2%2Ai%29=4%2Ai%5E2=4%28-1%29=-4.


9-6%2Ai-6%2Ai-4 Now collect every term to make a single expression.


5-12%2Ai Now combine like terms.


Now the number is in standard form a+bi where a=5 and b=-12


Rational-functions/148306: Solve 4x^2+20=0

1 solutions

Answer 108705 by jim_thompson5910(28598) About Me  on 2008-07-14 23:57:19 (Show Source):
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4x%5E2%2B20=0 Start with the given equation.


4x%5E2=0-20 Subtract 20 from both sides.


4x%5E2=-20 Combine like terms on the right side.


x%5E2=%28-20%29%2F%284%29 Divide both sides by 4 to isolate x%5E2.


x%5E2=-5 Reduce.



x=0%2B-sqrt%28-5%29 Take the square root of both sides.


x=sqrt%28-5%29 or x=-sqrt%28-5%29 Break up the expression.


x=i%2Asqrt%285%29 or x=-i%2Asqrt%285%29 Simplify the square root.


So our answers are x=i%2Asqrt%285%29 or x=-i%2Asqrt%285%29


Rational-functions/148305: Write in standard form: (1+i)-(8+3i)

1 solutions

Answer 108704 by jim_thompson5910(28598) About Me  on 2008-07-14 23:56:23 (Show Source):
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%281%2Bi%29-%288%2B3i%29 Start with the given expression.


1%2Bi-8-3i Distribute

%281-8%29%2B%28i-3i%29 Group like terms

-7-2i Combine like terms


Now the expression is in standard form a%2Bbi where a=-7 and b=-2


Rational-functions/148304: Write in standard form: (5+8i)/(6-i)

1 solutions

Answer 108703 by jim_thompson5910(28598) About Me  on 2008-07-14 23:55:15 (Show Source):
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Start with the given expression

Multiply the fraction by

Foil and Multiply


Break up the fraction.


So the expression is now in standard form a%2Bbi where a=22%2F37 and b=53%2F37


Rational-functions/148303: Solve 4x^2+5=-7

1 solutions

Answer 108702 by jim_thompson5910(28598) About Me  on 2008-07-14 23:52:44 (Show Source):
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4x%5E2%2B5=-7 Start with the given equation.


4x%5E2=-7-5 Subtract 5 from both sides.


4x%5E2=-12 Combine like terms on the right side.


x%5E2=%28-12%29%2F%284%29 Divide both sides by 4 to isolate x%5E2.


x%5E2=-3 Reduce.


x=0%2B-sqrt%28-3%29 Take the square root of both sides.


x=sqrt%28-3%29 or x=-sqrt%28-3%29 Break up the expression.


x=i%2Asqrt%283%29 or x=-i%2Asqrt%283%29 Simplify the square root.


So our answers are x=i%2Asqrt%283%29 or x=-i%2Asqrt%283%29


Rational-functions/148302: write in standard form: (8+5i)/(6-4i)

1 solutions

Answer 108701 by jim_thompson5910(28598) About Me  on 2008-07-14 23:51:24 (Show Source):
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%288%2B5i%29%2F%286-4i%29 Start with the given expression.


%28%288%2B5i%29%2F%286-4i%29%29%28%286%2B4i%29%2F%286%2B4i%29%29 Multiply the fraction by %286%2B4i%29%2F%286%2B4i%29


%28%288%2B5i%29%286%2B4i%29%29%2F%28%286-4i%29%286%2B4i%29%29 Combine the fractions.


%2848%2B62i%2B20i%5E2%29%2F%2836-16i%5E2%29 FOIL


%2848%2B62i%2B20%28-1%29%29%2F%2836-16%28-1%29%29 Replace i%5E2 with -1


%2848%2B62i-20%29%2F%2836%2B16%29 Multiply


%2828%2B62i%29%2F%2852%29 Combine like terms.


%2828%29%2F%2852%29%2B%2862i%29%2F%2852%29 Break up the fraction


7%2F13%2B%2831%2F26%29i Reduce


So the expression is now in a+bi form where a=7%2F13 and b=31%2F26


Rational-functions/148301: Identify the real and imaginary part:

14+9i

1 solutions

Answer 108700 by jim_thompson5910(28598) About Me  on 2008-07-14 23:49:48 (Show Source):
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Any complex number of the form a+bi has "a" as the real part and "b" as the imaginary part. So for the complex number 14+9i, the real part is a=14 and the imaginary part is b=9


Rational-functions/148299: (22 pts) Consider the polynomial f(x) = 2x^3 – 3x^2 – 8x – 3.
(i) By using the Rational Zero Theorem, list all possible rational zeros of the given polynomial.








(ii) Find all of the zeros of the given polynomial. Be sure to show work, explaining how you have found them.

1 solutions

Answer 108699 by jim_thompson5910(28598) About Me  on 2008-07-14 23:30:26 (Show Source):
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i)

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 -3 (the last coefficient):



Now let's list the factors of 2 (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







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


ii)

With the help of a graphing calculator, we see that -1 is a zero of 2x%5E3-3x%5E2-8x-3

note: let me know if you need to find the zeros a different way.

So let's set up a synthetic division table by placing the value -1 in the upper left corner and placing the coefficients of the polynomial to the right of -1.
-1|2-3-8-3
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 2)
-1|2-3-8-3
|
2

Multiply -1 by 2 and place the product (which is -2) right underneath the second coefficient (which is -3)
-1|2-3-8-3
|-2
2

Add -2 and -3 to get -5. Place the sum right underneath -2.
-1|2-3-8-3
|-2
2-5

Multiply -1 by -5 and place the product (which is 5) right underneath the third coefficient (which is -8)
-1|2-3-8-3
|-25
2-5

Add 5 and -8 to get -3. Place the sum right underneath 5.
-1|2-3-8-3
|-25
2-5-3

Multiply -1 by -3 and place the product (which is 3) right underneath the fourth coefficient (which is -3)
-1|2-3-8-3
|-253
2-5-3

Add 3 and -3 to get 0. Place the sum right underneath 3.
-1|2-3-8-3
|-253
2-5-30

Since the last column adds to zero, this means that -1 is a zero of 2x%5E3-3x%5E2-8x-3 (this confirms our original claim).



Now lets look at the bottom row of coefficients:

The first 3 coefficients (2,-5,-3) form the quotient

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


So %282x%5E3+-+3x%5E2+-+8x+-+3%29%2F%28x%2B1%29=2x%5E2+-+5x+-+3


Basically 2x%5E3+-+3x%5E2+-+8x+-+3 factors to %28x%2B1%29%282x%5E2+-+5x+-+3%29


Now lets find the zeros for 2x%5E2+-+5x+-+3.


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-%28-5%29+%2B-+sqrt%28+%28-5%29%5E2-4%282%29%28-3%29+%29%29%2F%282%282%29%29 Plug in a=2, b=-5, and c=-3


x+=+%285+%2B-+sqrt%28+%28-5%29%5E2-4%282%29%28-3%29+%29%29%2F%282%282%29%29 Negate -5 to get 5.


x+=+%285+%2B-+sqrt%28+25-4%282%29%28-3%29+%29%29%2F%282%282%29%29 Square -5 to get 25.


x+=+%285+%2B-+sqrt%28+25--24+%29%29%2F%282%282%29%29 Multiply 4%282%29%28-3%29 to get -24


x+=+%285+%2B-+sqrt%28+25%2B24+%29%29%2F%282%282%29%29 Rewrite sqrt%2825--24%29 as sqrt%2825%2B24%29


x+=+%285+%2B-+sqrt%28+49+%29%29%2F%282%282%29%29 Add 25 to 24 to get 49


x+=+%285+%2B-+sqrt%28+49+%29%29%2F%284%29 Multiply 2 and 2 to get 4.


x+=+%285+%2B-+7%29%2F%284%29 Take the square root of 49 to get 7.


x+=+%285+%2B+7%29%2F%284%29 or x+=+%285+-+7%29%2F%284%29 Break up the expression.


x+=+%2812%29%2F%284%29 or x+=++%28-2%29%2F%284%29 Combine like terms.


x+=+3 or x+=+-1%2F2 Simplify.


So the zeros of 2x%5E3-3x%5E2-8x-3 are x=-1, x=3, or x=-1%2F2


Rational-functions/148297: Use synthetic division to divide the polynomial 2x^3 – 7x + 10 by x + 3, and write the quotient polynomial and the remainder.
1 solutions

Answer 108698 by jim_thompson5910(28598) About Me  on 2008-07-14 23:17:30 (Show Source):
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Let's simplify this expression using synthetic division


Start with the given expression %282x%5E3+-+7x+%2B+10%29%2F%28x%2B3%29

First lets find our test zero:

x%2B3=0 Set the denominator x%2B3 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 2x%5E3 to -7x%5E1 there is a zero coefficient for x%5E2. This is simply because 2x%5E3+-+7x+%2B+10 really looks like 2x%5E3%2B0x%5E2%2B-7x%5E1%2B10x%5E0
-3|20-710
|

Start by bringing down the leading coefficient (it is the coefficient with the highest exponent which is 2)
-3|20-710
|
2

Multiply -3 by 2 and place the product (which is -6) right underneath the second coefficient (which is 0)
-3|20-710
|-6
2

Add -6 and 0 to get -6. Place the sum right underneath -6.
-3|20-710
|-6
2-6

Multiply -3 by -6 and place the product (which is 18) right underneath the third coefficient (which is -7)
-3|20-710
|-618
2-6

Add 18 and -7 to get 11. Place the sum right underneath 18.
-3|20-710
|-618
2-611

Multiply -3 by 11 and place the product (which is -33) right underneath the fourth coefficient (which is 10)
-3|20-710
|-618-33
2-611

Add -33 and 10 to get -23. Place the sum right underneath -33.
-3|20-710
|-618-33
2-611-23

Since the last column adds to -23, we have a remainder of -23. This means x%2B3 is not a factor of 2x%5E3+-+7x+%2B+10
Now lets look at the bottom row of coefficients:

The first 3 coefficients (2,-6,11) form the quotient

2x%5E2+-+6x+%2B+11

and the last coefficient -23, is the remainder, which is placed over x%2B3 like this

-23%2F%28x%2B3%29



Putting this altogether, we get:

2x%5E2+-+6x+%2B+11%2B-23%2F%28x%2B3%29

So %282x%5E3+-+7x+%2B+10%29%2F%28x%2B3%29=2x%5E2+-+6x+%2B+11%2B-23%2F%28x%2B3%29

which looks like this in remainder form:
%282x%5E3+-+7x+%2B+10%29%2F%28x%2B3%29=2x%5E2+-+6x+%2B+11 remainder -23



Functions/148258: John increased the area of his garden by 120 ft^2. The original garden was 12 ft. by 14 ft., and he increased the length and the width by the same amount. Find the exact dimensions of the new garden and approximate the dimensions in feet and inches.
1 solutions

Answer 108657 by jim_thompson5910(28598) About Me  on 2008-07-14 16:41:14 (Show Source):
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Let x=amount he increased the dimensions of his garden, A%5Bo%5D=area of original garden and A%5Bn%5D=area of new garden
Since the original garden is 12 ft by 14 ft, this means that the area of the original garden is

A%5Bo%5D=12%2A14=168

So A%5Bo%5D=168 which means that the area of the original garden is 168 ft^2


Because the area of the new garden is 120 ft^2 larger than the original garden, this means that A%5Bn%5D=A%5Bo%5D%2B120


A%5Bn%5D=168%2B120 Plug in A%5Bo%5D=168


A%5Bn%5D=288 Add


So the area of the new garden is 288 ft^2


Now since he increased the dimensions by some unknown amount, this means that the area of the new garden is equal to:

A%5Bn%5D=%2812%2Bx%29%2814%2Bx%29


288=%2812%2Bx%29%2814%2Bx%29 Plug in A%5Bn%5D=288


288=168%2B26x%2Bx%5E2 FOIL


0=168%2B26x%2Bx%5E2-288 Subtract 288 from both sides.


0=x%5E2%2B26x-120 Combine and rearrange the 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-%2826%29+%2B-+sqrt%28+%2826%29%5E2-4%281%29%28-120%29+%29%29%2F%282%281%29%29 Plug in a=1, b=26, and c=-120


x+=+%28-26+%2B-+sqrt%28+676-4%281%29%28-120%29+%29%29%2F%282%281%29%29 Square 26 to get 676.


x+=+%28-26+%2B-+sqrt%28+676--480+%29%29%2F%282%281%29%29 Multiply 4%281%29%28-120%29 to get -480


x+=+%28-26+%2B-+sqrt%28+676%2B480+%29%29%2F%282%281%29%29 Rewrite sqrt%28676--480%29 as sqrt%28676%2B480%29


x+=+%28-26+%2B-+sqrt%28+1156+%29%29%2F%282%281%29%29 Add 676 to 480 to get 1156


x+=+%28-26+%2B-+sqrt%28+1156+%29%29%2F%282%29 Multiply 2 and 1 to get 2.


x+=+%28-26+%2B-+34%29%2F%282%29 Take the square root of 1156 to get 34.


x+=+%28-26+%2B+34%29%2F%282%29 or x+=+%28-26+-+34%29%2F%282%29 Break up the expression.


x+=+%288%29%2F%282%29 or x+=++%28-60%29%2F%282%29 Combine like terms.


x+=+4 or x+=+-30 Simplify.


So the possible answers are x+=+4 or x+=+-30

However, since a negative length is not possible, this means that he increased his garden by 4 feet.


Now simply add 4 to each dimension 12 and 14 to get:

12+4=16 by 14+4=18

So the dimensions of the new garden are

16 ft by 18 ft


note: the approximate answers are the same as the exact answers since there are no square roots, fractions, decimals, etc. in the answer



Functions/148253: The velocity of sound is given by v=20%2Asqrt%28273t%5E6%29. Find the temperature when the velocity is 348 m/s
1 solutions

Answer 108651 by jim_thompson5910(28598) About Me  on 2008-07-14 16:24:34 (Show Source):
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v=20%2Asqrt%28273t%5E6%29 Start with the given equation.


348=20%2Asqrt%28273t%5E6%29 Plug in v=384


17.4=sqrt%28273t%5E6%29 Divide both sides by 20.


%2817.4%29%5E2=273t%5E6 Square both sides.


302.6=273t%5E6 Square 17.4 to get 302.6


1.10842=t%5E6 Divide both sides by 273.


root%286%2C1.10842%29=t Take the 6th root of both sides to isolate t.


1.0173=t Take the 6th root of 1.10842 to get 1.0173


t=1 Now round to the nearest degree

So when the temperature is 1 degree Celcius, then the approximate velocity of sound is 348 meters per second


Linear-equations/148220: 31. e^ln(3) =
s. 1
b. 2
c. 0
d. e
Can someone help me out with this?
Eddie


1 solutions

Answer 108622 by jim_thompson5910(28598) About Me  on 2008-07-14 12:46:04 (Show Source):
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Let y=ln(3). So this means that e^y=3


So

e^(ln(3))=e^y=3

So the answer is 3. I don't see "3" as an answer. So make sure that you wrote the problem correctly.


Equations/148216: Which of the following cannot be a base for exponential and logarithmic functions?
0.1
π
1
e

1 solutions

Answer 108621 by jim_thompson5910(28598) About Me  on 2008-07-14 12:43:18 (Show Source):
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The previous solution is correct, but there's more to this solution. Let's say that you could have a base of 1. So this means that 1%5Ex=y can be written as log%281%2C%28y%29%29=x by use of the property b%5Ey=x ===> log%28b%2C%28x%29%29=y


Now using the change of base formula, we can rewrite log%281%2C%28y%29%29=x as log%2810%2C%28y%29%29%2Flog%2810%2C%281%29%29=x. However, log%2810%2C%281%29%29=0 which means that log%2810%2C%28y%29%29%2Flog%2810%2C%281%29%29=x becomes log%2810%2C%28y%29%29%2F0=x. Since you cannot divide by zero, this means that a base of 1 is not possible for a logarithmic function.


Exponential-and-logarithmic-functions/148215: Determine x for 10^2x + 1 = 1000^x - 1
a. x = -2
b. x = 4
c. x = 9
d. No solution

1 solutions

Answer 108614 by jim_thompson5910(28598) About Me  on 2008-07-14 12:30:33 (Show Source):
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10%5E%282x+%2B+1%29+=+1000%5E%28x+-+1%29 Start with the given equation.


10%5E%282x+%2B+1%29+=+%2810%5E3%29%5E%28x+-+1%29 Rewrite 1000 as 10%5E3


10%5E%282x+%2B+1%29+=+10%5E%283%28x+-+1%29%29 Multiply the exponents.


10%5E%282x+%2B+1%29+=+10%5E%283x+-+3%29 Distribute.


2x%2B1=3x-3 Since the bases are equal, this means that the exponents are equal.


2x=3x-3-1 Subtract 1 from both sides.


2x-3x=-3-1 Subtract 3x from both sides.


-x=-3-1 Combine like terms on the left side.


-x=-4 Combine like terms on the right side.


x=%28-4%29%2F%28-1%29 Divide both sides by -1 to isolate x.


x=4 Reduce.


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

Answer:

So the answer is x=4


Graphs/148210: IN NEED OF HELP. I CANT SEEM TO GET THESE CAN ANYONE HELP? FIND THE SLOPE AND y-INTERCEPT OF THE GIVEN LINE. 1. 5y-2x+8=0 A. m = B. y-intercept 2. x=-9 A. m = B. y-intercept 3. 2x-7y=8 A. m = y-intercept D.y=5 A. m= B. y-intercept
1 solutions

Answer 108612 by jim_thompson5910(28598) About Me  on 2008-07-14 12:27:34 (Show Source):
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I'll do the first two to get you started.


# 1



5y-2x%2B8=0 Start with the given equation.


5y%2B8=0%2B2x Add 2x to both sides.


5y=0%2B2x-8 Subtract 8 from both sides.


5y=2x-8 Combine like terms on the right side.


y=%282x-8%29%2F%285%29 Divide both sides by 5 to isolate y.


y=%282%2F5%29x-%288%2F5%29 Break up the fraction.


Now the equation is in slope intercept form y=mx%2Bb where the slope is m=2%2F5 and the y-intercept is b=8%2F5






# 2

Since the equation x=-9 is not in slope intercept form, this means that the slope is undefined and there is no y-intercept (the line is parallel to the y-axis).


Polynomials-and-rational-expressions/148208: For all x=0 and y=0, (3x^3y^3)/xy=?
Multiple choose answers are
A. 9x^3y^8
B. 9y^4/x
C. 9y^4/x^2
D. 9y^5/x^5
E. 9y^7/x^5
What is the right answer
1 solutions

Answer 108610 by jim_thompson5910(28598) About Me  on 2008-07-14 12:22:12 (Show Source):
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%283x%5E3y%5E3%29%2F%28xy%29 Start with the given expression.


%283%2Ax%2Ax%2Ax%2Ay%2Ay%2Ay%29%2F%28x%2Ay%29 Expand. Remember, 3x%5E3y%5E3=3%2Ax%2Ax%2Ax%2Ay%2Ay%2Ay


Highlight the common terms.


%283%2Across%28x%29%2Ax%2Ax%2Across%28y%29%2Ay%2Ay%29%2F%28cross%28x%29%2Across%28y%29%29 Cancel out the common terms.


3%2Ax%2Ax%2Ay%2Ay Simplify.


3%2Ax%5E2%2Ay%5E2 Regroup.


So %283x%5E3y%5E3%29%2F%28xy%29 simplifies to 3%2Ax%5E2%2Ay%5E2.


I don't see this as an answer choice so double check the problem


Equations/148209: What is the domain of standard exponential functions?
a. x (0, ∞)
b. x (-∞, ∞)
c. x [0, ∞)
d. x (0, 1) (1, 2) (2, 3) (3, 4) (4, 5) .....

1 solutions

Answer 108608 by jim_thompson5910(28598) About Me  on 2008-07-14 12:19:18 (Show Source):
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If you graph a standard exponential function like y=2%5Ex, you get




From the graph, we can see that x can be any number. So the domain is b. x (-∞, ∞)


Equations/148207: If log a ≈ 0.250 and log b ≈ 0.644, then log b/a ≈
a. 2.576
b. 0.161
c. 0.394
d. There is insufficient information for a meaningful answer

1 solutions

Answer 108607 by jim_thompson5910(28598) About Me  on 2008-07-14 12:18:02 (Show Source):
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log (b/a)=log(b)-log(a)=0.644-0.250=0.394


So log (b/a)≈0.394


Equations/148206: Which of the following is a logarithmic function?
a. f(x) = x^2
b. L(t) = 1 - e^-t
c. g(q) = q^-2
d. R(x) = 4 ln(x)

1 solutions

Answer 108606 by jim_thompson5910(28598) About Me  on 2008-07-14 12:16:47 (Show Source):
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Remember, ln(x) is the natural log of x. So this means that d)R(x) = 4 ln(x) is a logarithmic function.


Equations/148205: Which of the following represents the numerical solution of: log2((4^2)(2^3)
a. 5
b. 12
c. 7
d. There is no numerical solution; this expression cannot be resolved

1 solutions

Answer 108605 by jim_thompson5910(28598) About Me  on 2008-07-14 12:15:52 (Show Source):
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log%282%2C%28%284%5E2%29%282%5E3%29%29%29 Start with the given expression.


log%282%2C%28%28%282%5E2%29%5E2%29%282%5E3%29%29%29 Rewrite 4 as 2%5E2


log%282%2C%28%282%5E4%29%282%5E3%29%29%29 Multiply the exponents.


log%282%2C%282%5E7%29%29 Multiply the terms by adding the exponents.


7%2Alog%282%2C%282%29%29 Rewrite the expression using the identity log%28b%2C%28x%5Ey%29%29=y%2Alog%28b%2C%28x%29%29.



7%2A1 Evaluate log%282%2C%282%29%29 to get 1


7 Multiply


So log%282%2C%28%284%5E2%29%282%5E3%29%29%29=7


Geometry_proofs/148202: Verify the identity.
a)(csc(-t)-sin(-t))/(sin(-t))=cot^(2)t
b)ln cotx= -ln tanx
1 solutions

Answer 108603 by jim_thompson5910(28598) About Me  on 2008-07-14 12:12:06 (Show Source):
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a)

Note: I'm only algebraically manipulating the left side. I'm showing the right side for comparison.

(csc(-t)-sin(-t))/(sin(-t))=cot^(2)t ... Start with the given equation


(1/sin(-t)-sin(-t))/(sin(-t))=cot^(2)t .... Replace csc(-t) with 1/sin(-t)


-(-1/sin(t)+sin(t))/(sin(t))=cot^(2)t .... Replace each sin(-t) with -sin(t)


(1/sin(t)-sin(t))/(sin(t))=cot^(2)t .... Simplify


(1/sin(t)-sin^2(t)/sin(t))/(sin(t))=cot^(2)t ... Rewrite sin(t) as sin^2(t)/sin(t)


((1-sin^2(t))/sin(t))/(sin(t))=cot^(2)t ... Combine the fractions in the numerator


((1-sin^2(t))/sin^2(t)=cot^(2)t ... Divide the fractions


(cos^2(t))/sin^2(t)=cot^(2)t ... Replace 1-sin^2(t) with cos^2(t)


cot^2(t)=cot^(2)t .... Replace (cos^2(t))/sin^2(t) with cot^2(t)


So this verifies the identity.



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

b)

Note: I'm only algebraically manipulating the left side. I'm showing the right side for comparison.



ln(cot(x))= -ln(tan(x)) ... Start with the given equation.


ln(1/tan(x))= -ln(tan(x)) ... Rewrite cot(x) as 1/tan(x)


ln((tan(x))^(-1))= -ln(tan(x)) ... Rewrite 1/tan(x) as (tan(x))^(-1)


-1*ln(tan(x))= -ln(tan(x)) ... Rewrite the left side using the identity ln%28x%5Ey%29=y%2Aln%28x%29%29


-ln(tan(x))= -ln(tan(x)) .... Multiply


So this verifies the identity.


Graphs/148204: solve the inequality 6+3y<4(3-x) for y and graph the solution. Please show me this step by step because I think I went wrong somewhere down the line, and I need to see where. Thanks in advance!
1 solutions

Answer 108601 by jim_thompson5910(28598) About Me  on 2008-07-14 12:05:31 (Show Source):
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6%2B3y%3C4%283-x%29 Start with the given inequality.


6%2B3y%3C12-4x Distribute.


3y%3C12-4x-6 Subtract 6 from both sides.


3y%3C-4x%2B6 Combine like terms on the right side.


y%3C%28-4x%2B6%29%2F%283%29 Divide both sides by 3 to isolate y.


y%3C%28-4x%29%2F%283%29%2B%286%29%2F%283%29 Break up the fraction.


y%3C-%284%2F3%29x%2B2 Reduce

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

Answer:

So the answer is y%3C-%284%2F3%29x%2B2



Now let's graph the equation y=-%284%2F3%29x%2B2 (replace the inequality sign with an equals sign)


+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C-%284%2F3%29x%2B2%29+ Graph of y=-%284%2F3%29x%2B2


Now plug in a test point (0,0) into the inequality y%3C-%284%2F3%29x%2B2


y%3C-%284%2F3%29x%2B2 Start with the given inequality.


0%3C-%284%2F3%29%2A%280%29%2B2 Plug in x=0 and y=0


0%3C2 Evaluate and simplify.


Since the inequality is true, this means that we shade the entire region that contains the point (0,0)


In other words, we simply shade the entire region that is below the line.


Graph of y%3C-%284%2F3%29x%2B2 with the shaded region in green



note: the boundary should be a dotted line.


Angles/148176: Please try to help me on this question:
If the measure of an angle is (7x-13)degree and the measure of its supplement is (5x-11)degree, find x.

1 solutions

Answer 108599 by jim_thompson5910(28598) About Me  on 2008-07-14 11:43:56 (Show Source):
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Since the two angles are supplementary, this means that the two angles add to 180 degrees. So this means that %287x-13%29%2B%285x-11%29=180


7x-13%2B5x-11=180 Start with the given equation.


12x-24=180 Combine like terms on the left side.


12x=180%2B24 Add 24 to both sides.


12x=204 Combine like terms on the right side.


x=%28204%29%2F%2812%29 Divide both sides by 12 to isolate x.


x=17 Reduce.


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

Answer:

So the answer is x=17


Linear-systems/148199: Write the equation of a line whose slope is 6 and whose y intercept is -3.
1 solutions

Answer 108597 by jim_thompson5910(28598) About Me  on 2008-07-14 11:39:12 (Show Source):
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Since the equation has a y intercept of -3, this means that the equation goes through the point (0,-3).



If you want to find the equation of line with a given a slope of 6 which goes through the point (0,-3), you can simply use the point-slope formula to find the equation:


---Point-Slope Formula---
y-y%5B1%5D=m%28x-x%5B1%5D%29 where m is the slope, and is the given point

So lets use the Point-Slope Formula to find the equation of the line

y--3=%286%29%28x-0%29 Plug in m=6, x%5B1%5D=0, and y%5B1%5D=-3 (these values are given)


y%2B3=%286%29%28x-0%29 Rewrite y--3 as y%2B3


y%2B3=6x%2B%286%29%28-0%29 Distribute 6

y%2B3=6x%2B0 Multiply 6 and -0 to get 0

y=6x%2B0-3 Subtract 3 from both sides to isolate y

y=6x-3 Combine like terms 0 and -3 to get -3
------------------------------------------------------------------------------------------------------------
Answer:


So the equation of the line with a slope of 6 which goes through the point (0,-3) is:

y=6x-3 which is now in y=mx%2Bb form where the slope is m=6 and the y-intercept is b=-3

Notice if we graph the equation y=6x-3 and plot the point (0,-3), we get (note: if you need help with graphing, check out this solver)

Graph of y=6x-3 through the point (0,-3)
and we can see that the point lies on the line. Since we know the equation has a slope of 6 and goes through the point (0,-3), this verifies our answer.


Graphs/148201: 1. Line j contains the points (-2,3) and (1,5).
a) Determine the slope of the line.---I got that part. slope=2/3
b) Write an equation for the line.
y=2/3x+ ???
I need help right there.
1 solutions

Answer 108595 by jim_thompson5910(28598) About Me  on 2008-07-14 11:36:24 (Show Source):
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First let's find the slope of the line through the points and


m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29 Start with the slope formula.


m=%285-3%29%2F%281--2%29 Plug in y%5B2%5D=5, y%5B1%5D=3, x%5B2%5D=1, x%5B1%5D=-2, ,


m=%282%29%2F%281--2%29 Subtract 3 from 5 to get 2


m=%282%29%2F%283%29 Subtract -2 from 1 to get 3


So the slope of the line that goes through the points and is m=2%2F3


Now let's use the point slope formula:


y-y%5B1%5D=m%28x-x%5B1%5D%29 Start with the point slope formula


y-3=%282%2F3%29%28x--2%29 Plug in m=2%2F3, x%5B1%5D=-2, and y%5B1%5D=3


y-3=%282%2F3%29%28x%2B2%29 Rewrite x--2 as x%2B2


y-3=%282%2F3%29x%2B%282%2F3%29%282%29 Distribute


y-3=%282%2F3%29x%2B4%2F3 Multiply


y=%282%2F3%29x%2B4%2F3%2B3 Add 3 to both sides.


y=%282%2F3%29x%2B4%2F3%2B9%2F3 Rewrite 3 as 9%2F3.


y=%282%2F3%29x%2B13%2F3 Combine the fractions.



So the equation that goes through the points and is y=%282%2F3%29x%2B13%2F3


Notice how the graph of y=%282%2F3%29x%2B13%2F3 goes through the points and . So this visually verifies our answer.
Graph of y=%282%2F3%29x%2B13%2F3 through the points and