Application of revenue and cost function.

• Dec 10th 2008, 10:35 AM
jdv214
Application of revenue and cost function.
well first it would help if I knew how to type the math equation so if you can answer that it will help me in the future.. Here is the question.

daily revenue: R(x)=x^2-18
Daily Cost: C(x)=75+4x

How many items must be made and sold daily in order to break even.

I'm not sure what to do with this problem so any help to steer me in the correct direction is appreciated.

• Dec 10th 2008, 01:38 PM
skeeter
the break even point is when revenue = cost

$x^2 - 18 = 75 + 4x$

you'll need to use the quadratic formula to solve for x
• Dec 10th 2008, 01:40 PM
jdv214
x=25!!!

thanks
• Dec 10th 2008, 01:57 PM
skeeter
Quote:

Originally Posted by jdv214
x=25!!!

thanks

how did you get x = 25?
• Dec 10th 2008, 02:02 PM
jdv214
I posted the original problem wrong. by forgetting the 'x' after 18. So...

x^2-18x-(75+4x)=0
x^2-22X-75=0
(X-25)(X+3)=0
x=25

When i plug that number back into the equation I get
R(x)=175
C(x)=175

It must be the correct answer.
• Dec 10th 2008, 04:45 PM
skeeter
Quote:

Originally Posted by jdv214
I posted the original problem wrong by forgetting the 'x' after 18.

that would explain it.