How do you get the volume of an expanding object?(adsbygoogle = window.adsbygoogle || []).push({});

For example:

A sphere's is increasing at 12ft/sec, the volume is 36, how fast is the surface area of a sphere

V=4*pi*r^3/3 S=4*pi*r^2

dV/dt= 12

So i took the derivative of the volume function

dV/dt=4*pi*r^2*dr/dt

12=4*pi*r^2*dr/dt

how do you solve for dr/dt

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# Volumes by revolutions

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