# Math Help - Rate of Change

1. ## Rate of Change

A spherical baloon is being filled at a rate of cm /s. At what rate is the surface area expanding when the radius is cm?

V = 4/3*Pi*r^3

V=4*Pi*r^2*r

r= V/(4Pi*r^2)

V = 10, r = 11

r = 5/(242*Pi) cm/s

Is this correct???

2. ## Re: Rate of Change

we have been asked to find the rate at which the surface area is expanding.

3. ## Re: Rate of Change

No. The question is to calculate the rate of change of the surface at R = 11 cm3.

thx guys