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funmath answered: 2925 problems
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Polynomials-and-rational-expressions/687205: what is 15y3+6y2+3y divided 3y when you simplify

1 solutions

Answer 425072 by funmath(2925) About Me  on 2012-11-29 18:01:16 (Show Source):
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what is 15y3+6y2+3y divided 3y when you simplify
%2815y%5E3%2B6y%5E2%2B3y%29%2F%283y%29
Because the bottom is a monomial we can separate the terms like this:
15y%5E3%2F%283y%29%2B6y%5E2%2F%283y%29%2B3y%2F%283y%29
Divide and you get:
highlight%285y%5E2%2B2y%2B1%29
Happy Calculating!!!


Percentage-and-ratio-word-problems/687189: what is 14% as a ratio
1 solutions

Answer 425066 by funmath(2925) About Me  on 2012-11-29 17:42:25 (Show Source):
You can put this solution on YOUR website!
What is 14% as a ratio?
We can write %'s as fractions by putting 100 under them.
14%2F100
Reduce the top and bottom by 2
7%2F50
Sometimes, they prefer to to write them this way: 7:50
Happy Calculating!


expressions/687147: (X2-3x+7)+(3x2+5x-9)
1 solutions

Answer 425064 by funmath(2925) About Me  on 2012-11-29 17:39:42 (Show Source):
You can put this solution on YOUR website!
%28x%5E2-3x%2B7%29%2B%283x%5E2%2B5x-9%29
Combine like terms
x%5E2%2B3x%5E2-3x%2B5x%2B7%2B%28-9%29
highlight%284x%5E2%2B2x-2%29
Happy Calculating!!!


Expressions-with-variables/687150: solve tthis problem (+7)-(-3)+(+16)-(+8)
1 solutions

Answer 425060 by funmath(2925) About Me  on 2012-11-29 17:29:56 (Show Source):
You can put this solution on YOUR website!
solve this problem (+7)-(-3)+(+16)-(+8)
To me...all the extra parentheses confuse things...but some people like them...I remove them. + keeps the sign in the parenthesis the same - makes it opposite.
%28%2B7%29-%28-3%29%2B%28%2B16%29-%28%2B8%29
7%2B3%2B16-8
10%2B16-8
26-8
highlight%2818%29
I took more steps than necessary to show you...I just combined the 2 numbers on the left as I went down.
Happy Calculating!


expressions/687088: I have the find the LCD and then find equivilant fractions to the fractions.
(4a+1)/(7a^(3)),(5a-1)/(49a)
1 solutions

Answer 425040 by funmath(2925) About Me  on 2012-11-29 16:13:44 (Show Source):
You can put this solution on YOUR website!
Find the LCD and then find equivalent fractions to the fractions.
%284a%2B1%29%2F%287a%5E%283%29%29,%285a-1%29%2F%2849a%29
First find the factors of the denominators:
7a%5E3=7%2Aa%2Aa%2Aa
49a=7%2A7a
They have a 7 and an a in common so don't count them twice.
LCD=7%2A7%2Aa%2Aa%2Aa=49a%5E3
Notice that we took the highest power of the things they had in common.
What ever you have to multiply the denominators by to get the LCD, you have to multiply by the numerators as well.
7%284a%2B1%29%2F%287%2A%287a%5E3%29%29, a%5E2%285a-1%29%2F%28a%5E2%2A%2849a%29%29
%2828a%2B7%29%2F%2849a%5E3%29,%285a%5E3-a%5E2%29%2F%2849a%5E3%29
Happy Calculating!!!


Linear-equations/687077: -6x+y=-4 find the slope and y-intercept
1 solutions

Answer 425037 by funmath(2925) About Me  on 2012-11-29 15:55:54 (Show Source):
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-6x+y=-4 find the slope and y-intercept
The slope intercept form of a line is:
y=mx+b where m = slope and (0,b) = y-intercept
So...solve the equations for y:
-6x%2By=-4
add 6x to both sides of the equation.
6x-6x%2By=6x-4
y=6x-4
The 6 is in the m spot...it is the slope.
The -4 is in the b spot...it is the y coordinate of the y-intercept. (0,-4)
Happy Calculating!!!


Linear-equations/687102: Find slope : (1,-4) , (6, -2)
1 solutions

Answer 425031 by funmath(2925) About Me  on 2012-11-29 15:45:51 (Show Source):
You can put this solution on YOUR website!
Find slope : (1,-4) , (6, -2)
When you have two points (x1,y1), (x2,y2)
The formula for slope (We call it m) is:
highlight%28m=%28y2-y1%29%2F%28x2-x1%29%29
m=%28-2-%28-4%29%29%2F%286-1%29
m=%28-2%2B4%29%2F%286-1%29
highlight%28m=2%2F5%29
Happy Calculating!


Triangles/687104: My math homework says.... Draw a right triangle. One of the legs measures 8cm. The other leg measures 6cm. What is the length of the hypotenuse? Thank You
1 solutions

Answer 425029 by funmath(2925) About Me  on 2012-11-29 15:38:23 (Show Source):
You can put this solution on YOUR website!
Draw a right triangle. One of the legs measures 8cm. The other leg measures 6cm. What is the length of the hypotenuse?
I can't really draw a right triangle for you here, but the Pythagorean Theorem helps us to find the hypotenuse: (leg)^2+(other leg)^2=(hypotenuse)^2
Usually, we use a and b for the legs and c for the hypotenuse.
highlight%28a%5E2%2Bb%5E2=c%5E2%29
8%5E2%2B6%5E2=c%5E2
64%2B36=c%5E2
100=c%5E2
sqrt%28100%29=sqrt%28c%5E2%29
10=c
The hypotenuse is 10 cm.
Happy Calculating!


Polynomials-and-rational-expressions/687074: Find a positive value of C so that the following trinomial is factorable.
x^2-7x+c
1 solutions

Answer 425024 by funmath(2925) About Me  on 2012-11-29 15:28:01 (Show Source):
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Find a positive value of C so that the following trinomial is factorable.
x^2-7x+c
In order to be able to factor this...we need to split the -7 into two numbers that will add back together and get -7. Because c has to be positive, and we need to be able to multiply those same two numbers back together to get it, both numbers have to be negative. There are several possibilities:
(-1)(-6)=highlight%286%29
(-2)(-5)=highlight%2810%29
(-3)(-4)=highlight%2812%29
Any of them will work:
x%5E2-7x%2B6=%28x-1%29%28x-6%29
x%5E2-7x%2B10=%28x-2%29%28x-5%29
x%5E2-7x%2B12=%28x-3%29%28x-4%29
I hope that cleared things up.


Trigonometry-basics/687087: verify that the equations are identitites:
sinx + tanx = tanx (1+cosx)

1 solutions

Answer 425020 by funmath(2925) About Me  on 2012-11-29 15:09:50 (Show Source):
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verify that the equations are identitites:
sinx + tanx = tanx (1+cosx)
There is a trig identity you have to know to prove this.
highlight%28tan%28x%29=%28sin%28x%29%29%2F%28cos%28x%29%29%29
The rule of thumb is to try to use identities and properties in math to make the more complicated side look like the less complicated side....so attack the right side of the equation.
use the identity to replace tan(x)

Distribute

The cos(x) cancels
sin%28x%29%2Btan%28x%29=%28sin%28x%29%29%2F%28cos%28x%29%29%2Bsin%28x%29
Then use the identity again only we are replacing sin(x)/cos(x).
sin%28x%29%2Btan%28x%29=highlight%28tan%28x%29%29%2Bsin%28x%29
Addition is commutative, so...
sin%28x%29%2Btan%28x%29=sin%28x%29%2Btan%28x%29
Happy Calculating!!!


Coordinate-system/686355: Graph line with given point and slope.the line through (2,1)with slope 5/3.
please let me know to graph this?
Thank you
1 solutions

Answer 424755 by funmath(2925) About Me  on 2012-11-28 10:41:53 (Show Source):
You can put this solution on YOUR website!
Graph line with given point and slope.the line through (2,1)with slope 5/3.
please let me know to graph this?

You need two points to graph a line. The first point is (2,1)


We can get the second point if we know that slope = rise/run. It is helpful to let your rise be either positive or negative...and always run to the right.


Our y's are up and down...our rise...so if you add 5 to 1, you get 6.


Our x's are left and right...our run...so if you add 3 to 2, you get 5.


so our second point is (5,6)


connect the points but keep going to the end of the graph.

graph%28300%2C200%2C-10%2C10%2C-10%2C10%2C%285%2F3%29x-7%2F3%29
Hope that was clear. Happy calculating!!!


real-numbers/686359: Are all whole numbers intergers?

1 solutions

Answer 424753 by funmath(2925) About Me  on 2012-11-28 10:32:09 (Show Source):
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Yes.
Integers are like whole numbers, but they also include negative numbers ... but still no fractions allowed!
So, integers can be negative {-1, -2,-3, -4, -5, … }, positive {1, 2, 3, 4, 5, … }, or zero {0}
We can put that all together like this:
Integers = { ..., -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, ... }


Numbers_Word_Problems/686362: The larger of two numbers is 9 more than the smaller. Their sum is 95

1 solutions

Answer 424752 by funmath(2925) About Me  on 2012-11-28 10:28:01 (Show Source):
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The larger of two numbers is 9 more than the smaller. Their sum is 95.

If we called the smaller number n, then the larger would be n+9


larger + smaller = 95

%28n%2B9%29%2Bn=95
2n%2B9=95
2n%2B9-9=95-9
2n=86
2n%2F2=86%2F2
n=43
The smaller number is n=highlight%2843%29
The larger number is n+9 or 43+9=highlight%2852%29
****************************************************
Sanity check...do the two numbers really add to 95?
43+52 does equal 95, so we are not completely crazy :)


Quadratic_Equations/685998: Solve for x by completing the square
2x^2+20=4x
1 solutions

Answer 424678 by funmath(2925) About Me  on 2012-11-27 18:00:07 (Show Source):
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Solve for x by completing the square
2x%5E2%2B20=4x
First get the x's together and the constant on the other side.
2x%5E2-4x=-20
Then divide the whole equation by any coefficient in front of the x^2...in this case, 2.
2x%5E2%2F2-4x%2F2=-20%2F2
x%5E2-2x=-10
At this point, if we call the coefficient of x, b....then we would add (b/2)^2 to both sides.
%28b%2F2%29%5E2=%28-2%2F2%29%5E2 -> %28-1%29%5E2=1
x%5E2-2x%2B1=-10%2B1
Factor the left and simplify the right. Perfect squares always factor to be the sqrt or the front and back with the sign that is in front of the x term between them...like this.
%28x-1%29%5E2=-9
Take the square root of both sides...don't forget it is always + or -.
sqrt%28%28x-1%29%5E2%29=+ or - sqrt%28-9%29
If you are only allowed to use "real" solutions...you are done...there is no "real" solution. However, if you are using imaginary or complex numbers...keep going as follows:
x-1= + or -3i
x=1 + or -3i
This is two answers:
highlight%28x=1-3i%29 or highlight%28x=1%2B3i%29
Happy Calculating!!!!


logarithm/685988: Please help me with this logarithmic equation: log to the base "x" (64) = 3
1 solutions

Answer 424674 by funmath(2925) About Me  on 2012-11-27 17:44:35 (Show Source):
You can put this solution on YOUR website!
log to the base "x" (64) = 3
logb(a)=m can be rewritten as b%5Em=a
x%5E3=64
At this point you can either take the cubed root of both sides of the equation, or raise both sides of the equation to the 1/3 power...it's easiest to type this way...but either is valid.
%28x%5E3%29%5E%281%2F3%29=%2864%29%5E%281%2F3%29
x=%284%5E3%29%5E%281%2F3%29
highlight%28x=4%29
Happy Calculating!!!!


Functions/685987: f(x)=sqrt 3x ; g(x)=sqrt 12x
solve:
(f+g)(x)
I thought (3+12)sqrt x but thats not it.
1 solutions

Answer 424672 by funmath(2925) About Me  on 2012-11-27 17:37:55 (Show Source):
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f(x)=sqrt%283x%29 ; g(x)=sqrt%2812x%29
solve:
(f+g)(x)=sqrt%283x%29%2Bsqrt%2812x%29
(f+g)(x)=sqrt%283x%29%2Bsqrt%284%2A3x%29
(f+g)(x)=sqrt%283x%29%2B2sqrt%283x%29
(f+g)(x)=highlight%283sqrt%283x%29%29
***********************************
Explanation....first you simplify the radicals. You can only add and subtract like terms. Radicals are only like terms when the indexes and roots are exactly the same.
Happy Calculating!


absolute-value/685951: How do i do |3x-1|+10=12 ?
1 solutions

Answer 424670 by funmath(2925) About Me  on 2012-11-27 17:31:38 (Show Source):
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How do i do |3x-1|+10=12 ?
First isolate the absolute value.
|3x-1|+10-10=12-10
|3x-1|=2
Then because the stuff inside of the absolute value can be + or - 2 to get 2, you set the inside equal to them both and solve 2 equations.
3x-1=-2 or 3x-1=2
3x-1%2B1=-2%2B1 or 3x-1%2B1=2%2B1
3x=-1 or 3x=3
3x%2F3=-1%2F3 or 3x%2F3=3%2F3
highlight%28x=-1%2F3%29 or highlight%28x=1%29
*****************************************************
It seems not to make sense to do that...but let's check to see that both answers are correct:
for x=-1/3
|3(-1/3)-1|+10=12
|-1-1|+10=12
|-2|+10=12
12=12 True....so x=-1/3 for sure.
for x=1
|3(1)-1|+10=12
|3-1|+10=12
|2|+10=12
2+10=12
12=12 True....so x also can = 1
Often teaches want set notation of x={-1/3,1}
Happy Calculating!!!


test/685776: Simplest form of radical expression. Please explain
3 square root 24 - 2 square root 54 + 2 square root 18
1 solutions

Answer 424573 by funmath(2925) About Me  on 2012-11-27 10:51:29 (Show Source):
You can put this solution on YOUR website!
Simplest form of radical expression. Please explain
3 square root 24 - 2 square root 54 + 2 square root 18
3sqrt%2824%29-2sqrt%2854%29%2B2sqrt%2818%29
You can either look for perfect squares, and take the square root of that part...or use any prime factors that you two of.
3sqrt%282%2A2%2A2%2A3%29-2sqrt%282%2A3%2A3%2A3%29%2B2sqrt%282%2A3%2A3%29
3sqrt%284%2A6%29-2sqrt%289%2A6%29%2B2sqrt%289%2A2%29
3sqrt%284%29sqrt%286%29-2sqrt%289%29sqrt%286%29%2B2sqrt%289%29sqrt%282%29
3%282%29sqrt%286%29-2%283%29sqrt%286%29%2B2%283%29sqrt%282%29
6sqrt%286%29-6sqrt%286%29%2B6sqrt%282%29
The only ones you can add and subtract are the like terms. They have to have the same indexes and roots in order to add them.
%286-6%29sqrt%286%29%2B6sqrt%282%29
0%2B6sqrt%282%29
highlight%286sqrt%282%29%29
Hope that was clear...wish I could point and talk to explain. lol


Square-cubic-other-roots/685214: what is the answer to "what is the square root of z to the 20th?"
1 solutions

Answer 424379 by funmath(2925) About Me  on 2012-11-26 14:18:22 (Show Source):
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"what is the square root of z to the 20th?"
Squares and square roots cancel each other.
sqrt%28z%5E20%29
sqrt%28%28z%5E10%29%5E2%29
highlight%28z%5E10%29
Happy Calculating!!!


logarithm/685192: Can you solve these two questions?

log10 (1/100) and
log5 5/5


1 solutions

Answer 424378 by funmath(2925) About Me  on 2012-11-26 14:14:35 (Show Source):
You can put this solution on YOUR website!
Can you solve these two questions?

log10 (1/100) and
log5 5/5
I am not sure I am reading this the way you intend...but if I am.... logb+%28b%5Em%29=m
so...
log10%281%2F100%29
log10%281%2F10%5E2%29
log10%2810%5E-2%29
highlight%28-2%29
***************************************************************
log5+%285%2F5%29
log5+%285%5E%281-1%29%29
log5+%285%5E0%29
highlight%280%29
Happy Calculating!!!


Quadratic_Equations/685206: what value should be added to each side to complete the square of:
x^2+20x=-8
1 solutions

Answer 424377 by funmath(2925) About Me  on 2012-11-26 14:05:00 (Show Source):
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what value should be added to each side to complete the square of:
x^2+20x=-8
When you have a binomial in this form:
x%5E2%2Bbx
There is a formula that tells you what will complete the square: c=%28b%2F2%29%5E2
For us...b=20
c=%2820%2F2%29%5E2
c=10%5E2
highlight%28c=100%29
************************************************************************
x%5E2%2B20x%2B100=-8%2B100
%28x%2B10%29%5E2=98
Some find it easier to visualize the end...guessing what it has to be to make a perfect square...that falls apart for most when fractions and decimals are introduced.
Happy Calculating!!!


Complex_Numbers/685129: Find the product of (4+5i) and (4-5i) What are pairs of complex numbers like these called?
1 solutions

Answer 424350 by funmath(2925) About Me  on 2012-11-26 11:23:10 (Show Source):
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Find the product of (4+5i) and (4-5i) What are pairs of complex numbers like these called?
These are called "conjugates" of each other because they are the same binomials with opposite signs in the middle.
You need to know that highlight%28i%5E2=-1%29 then you can foil as always...but conjugates always multiply to be the difference of squares...so it is not necessary...but it works every time.
%284%2B5i%29%284-5i%29
4%284-5i%29%2B5i%284-5i%29
16-20i%2B20i-25i%5E2
16-25i%5E2
The above is the difference of squares that you can skip to for conjugates.
16-25%28-1%29
16%2B25
highlight%2841%29
Happy Calculating!!!


Linear-systems/685128: qual é o resultado da
-5x-2(-3x-4)=-5x-2
1 solutions

Answer 424348 by funmath(2925) About Me  on 2012-11-26 11:14:35 (Show Source):
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qual é o resultado da
-5x-2(-3x-4)=-5x-2
First simplify both sides of the equation using the orders of operation.
En primer lugar simplificar ambos lados de la ecuación utilizando las órdenes de operación.
-5x%2B6x%2B8=-5x-2
x%2B8=-5x-2
Then move the variables to one side and the constants to the other by adding their inverses to both sides of the equation.
Luego mover las variables a un lado y las constantes a la otra mediante la adición de sus inversos a ambos lados de la ecuación.
5x%2Bx%2B8=5x-5x-2
6x%2B8=-2
6x%2B8-8=-2-8
6x=-10
Last divide by the number being multiplied by the variable.
Última divide por el número que se multiplica por la variable.
6x%2F6=-10%2F6
highlight%28x=-5%2F3%29
¡Buena suerte!


Percentage-and-ratio-word-problems/685076: The numerator of a fraction is 4 less than its denominator. If you add 1 to both the numerator and the denominator, the resulting fraction is equal to 2/3. What is the original fraction?
1 solutions

Answer 424325 by funmath(2925) About Me  on 2012-11-26 09:10:57 (Show Source):
You can put this solution on YOUR website!
The numerator of a fraction is 4 less than its denominator. If you add 1 to both the numerator and the denominator, the resulting fraction is equal to 2/3. What is the original fraction?

Let the denominator = x


Then the numerator is 4 less than that: x-4


If you add 1 to the denominator you have: x+1


If you add one to the numerator you have: x-4+1 or x-3

So your algebraic equation is:
%28x-3%29%2F%28x%2B1%29=2%2F3
Cross Multiply:
3%28x-3%29=2%28x%2B1%29
3x-9=2x%2B2
3x-2x-9=2x-2x%2B2
x-9=2
x-9%2B9=2%2B9
x=11
Your denominator is x=11
Your numerator is: x-4=11-4=7
The original fraction is: highlight%287%2F11%29

Do a sanity check...if you add 1 to the numerator and denominator, does it indeed reduce to 2/3's?

Happy Calculating!


Angles/685068: two lines intersect forming four angles. one of the angles measures 36 degrees find the measurement of the other three angles
1 solutions

Answer 424324 by funmath(2925) About Me  on 2012-11-26 08:41:59 (Show Source):
You can put this solution on YOUR website!
Vertical angles are equal to each other....so the angle opposite of the 36 degree angle is also 36 degrees.
Adjacent angles form a straight line of 180 degree...so the angle next to the 36 degree angle is 180-36 = 144 degrees
The angle opposite of the 144 degree angle is also 144 degrees.
So the four angles are: 36, 144, 36, 144 degrees.
Happy Calculating. :)


test/682845: -7v+5_>-79
1 solutions

Answer 423349 by funmath(2925) About Me  on 2012-11-19 16:08:04 (Show Source):
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-7v+5_>-79
-7v+5-5_>-79-5
-7v_>-84
Reverse the inequality symbol when you multiply or divide both sides of an inequality by a negative number.
-7v%2F-7_<-84%2F-7
v_<12
Happy Calculating!


Equations/682824: Thank you for the help, i need it, thank you, thank you.
Alexander and Judy are 31 miles apart on a calm lake paddling toward each other.
Alexander paddles at 5 miles per hour, while Judy paddles at 8 miles per hour. How long will it take them to meet?
1 solutions

Answer 423347 by funmath(2925) About Me  on 2012-11-19 15:41:12 (Show Source):
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Alexander and Judy are 31 miles apart on a calm lake paddling toward each other.
Alexander paddles at 5 miles per hour, while Judy paddles at 8 miles per hour. How long will it take them to meet?
Assuming that they left at the same time: Distance = rate*time
Let t = time in hours
Alexander's distance: 5t
Judy's distance: 8t
total distance: 31
5t%2B8t=31
13t=31
t=31%2F13
t= 2.3846 hours
or
t= 2hrs+60(.3846)mins
t=2hrs and 23 mins
Barring any fatal careless errors, that should be it.
Happy Calculating!!!


Equations/682817: Solve this equation for x with working:
(x+3)/(x+5)=(x+1)/(x+2)
1 solutions

Answer 423346 by funmath(2925) About Me  on 2012-11-19 15:29:06 (Show Source):
You can put this solution on YOUR website!
%28x%2B3%29%2F%28x%2B5%29=%28x%2B1%29%2F%28x%2B2%29
You can cross multiply when you have a fraction equal to another, however multiplying both sides by the LCD works every time for rational equations.
The LCD is (x+5)(x+2)

The denominators cancel:
%28x%2B2%29%28x%2B3%29=%28x%2B5%29%28x%2B1%29
Foil and solve:
x%5E2%2B2x%2B3x%2B6=x%5E2%2Bx%2B5x%2B5
x%5E2%2B5x%2B6=x%5E2%2B6x%2B5
-x%5E2%2Bx%5E2%2B5x%2B6=-x%5E2%2Bx%5E2%2B6x%2B5
5x%2B6=6x%2B5
-5x%2B5x%2B6=-5x%2B6x%2B5
6=x%2B5
6-5=x%2B5-5
1=x
highlight%28x=1%29
*Note* Always check and make sure that your answer does not make any denominator 0...that makes fractions undefined. If you had gotten -5 or -2, then there would be no solution.
Happy Calculating.


Travel_Word_Problems/682777: I need help on this calculus word problem:
Two ants are at a common point at time t=0, the first ant starts crawling along a straight line at the rate of 4 ft/min. Two minutes later, the second ant starts crawling in a direction perpendicular to that of the first, at a rate of 5 ft/min. How fast is the distance between them changing when the first insect has traveled 12 feet?
Thank you!
1 solutions

Answer 423333 by funmath(2925) About Me  on 2012-11-19 14:58:09 (Show Source):
You can put this solution on YOUR website!
Two ants are at a common point at time t=0, the first ant starts crawling along a straight line at the rate of 4 ft/min. Two minutes later, the second ant starts crawling in a direction perpendicular to that of the first, at a rate of 5 ft/min. How fast is the distance between them changing when the first insect has traveled 12 feet?

Let r be the distance between them, x be the distance of the first and y be the distance of the second. Then according to the Pythagorean theorem:

r%5E2=x%5E2%2By%5E2
Taking the derivative of the equation with respect to time yields:
2r%28dr%2Fdt%29=2x%28dx%2Fdt%29%2B2y%28dy%2Fdt%29
Everything is divisible by 2 so divide the whole thing by 2 to make things easier.
highlight%28r%28dr%2Fdt%29=x%28dx%2Fdt%29%2By%28dy%2Fdt%29%29
Now use a little algebra to find the missing components.
Given:
dx%2Fdt=4the rate of the first ant
dy%2Fdt=5the rate of the second ant
x=12 the distance the first ant traveled.

distance = rate*time

We get t from the first ant.
12=4t
12%2F4=4t%2F4
3=t
Therefore the second ant traveled.
y=5%28t-2%29
y=5%28highlight%283%29-2%29
y=5

We use the Pythagorean Theorem to find r

r%5E2=x%5E2%2By%5E2
r%5E2=12%5E2%2B5%5E2
r%5E2=144%2B25
r%5E2=169
r=sqrt%28169%29
r=13
Take all the parts and put them into the equation you took the derivative of.
highlight%28r%28dr%2Fdt%29=x%28dx%2Fdt%29%2By%28dy%2Fdt%29%29
13%28dr%2Fdt%29=12%284%29%2B5%285%29
13%28dr%2Fdt%29=48%2B25
13%28dr%2Fdt%29=73
dr%2Fdt=73%2F13
dr%2Fdt=5.6ft/min
That should be it barring any careless mistakes. Happy Calculating!


Trigonometry-basics/682759: Using one of the sum and difference identities, find the exact value of:
cos(30degrees+45degrees)
1 solutions

Answer 423318 by funmath(2925) About Me  on 2012-11-19 14:10:35 (Show Source):
You can put this solution on YOUR website!
highlight%28cos%28a%2Bb%29=cos%28a%29cos%28b%29-sin%28a%29sin%28b%29%29
cos%2830%2B45%29=cos%2830%29cos%2845%29-sin%2830%29sin%2845%29
Use your unit circle or 45,45,90 and 30,60,90 triangles to evaluate:
cos%2830%2B45%29=%28sqrt%283%29%2F2%29%28sqrt%282%29%2F2%29-%281%2F2%29%28sqrt%282%29%2F2%29
Simplify:
highlight%28cos%2830%2B45%29=%28sqrt%286%29-sqrt%282%29%29%2F4%29


Radicals/682767: √127x^10/√81y^6
i need to find the solution in its simplified radical form, with work please.
1 solutions

Answer 423317 by funmath(2925) About Me  on 2012-11-19 14:02:21 (Show Source):
You can put this solution on YOUR website!
sqrt%28127x%5E10%29%2Fsqrt%28%2881y%5E6%29%29
Find the squares within the square roots:
sqrt%28127%28x%5E5%29%5E2%29%2Fsqrt%28%289y%5E3%29%5E2%29
Square roots cancel squares:
highlight%28x%5E5sqrt%28127%29%2F%289y%5E3%29%29