Sunday

March 1, 2015

March 1, 2015

Posted by **Anonymous** on Sunday, November 18, 2007 at 12:43am.

Here is what I did: (unsure)

pi(r^2)=2pi(r)

r^2-r=0

r(r-2)=0

r=2

- calculus -
**Reiny**, Sunday, November 18, 2007 at 1:20amno, it is the rates of increase that are equal, so you have to set the derivatives equal.

dA/dr = 2pi(r)

dC/dr = 2pi

so 2pi(r) = 2 pi

r = 1

**Answer this Question**

**Related Questions**

Calculus - The radius of a circle is increasing. At a certain instant, the rate ...

businessmathamatics - using derivative as a rate measure prove the following'if ...

calculas - At time t=0 s, the radius of a circle is equal to 15 cm. The radius ...

Calculus I - Let A be the area of a circle with radius r that is increasing in ...

Precalculus - Hey so I need help on a problem from an assignment that my ...

Algebra - The area of a circle is given by the formula A+pier^2, where r is the ...

AP Calculus - Oil leaks out from a damaged oil tanker and forms a circle around ...

college calculus - 1) each side of a square is increasing at a rate of 6cm/s. At...

Calculus - A spherical balloon is inflated at a rate of 10 cubic feet per minute...

?Cal/Trig?? - Suppose the circumference of a circle is increasing at a rate of 3...