Question

the radius of a circle is decreasing at a constant rate of .1 centimeter per second. in terms of circumference C, what is the rate of change of the area of the circle, in square centimeters per second?

Answer 1

yup. then mukltiply by whatever coefficents there are for your 4 numbers

Answer 2

A = pi*r^2; dA/dt = 2*pi*r*dr/dt. We know dr/dt = 0.1cm/sec. We need to know the 'r' at which we want to determine the change in area (dA/dt) and stick that into the equation: dA/dt = 2*pi*r*dr/dt

Answer 3

wait, why do you multiply dr/dt

Answer 4

seocnd statement after Area formula

Answer 5

This is a related rate problem. The dA/dt is related to the dr/dt, which is a given.

Answer 6

Yes, you want dA/dt, which equals 2*pi*r*dr/dt

Answer 7

so..
the anser is -.1(2pirR)

Answer 8

WAIT NO