Question 1006602
{{{A=pi*r^2}}}
A for area is a function of time t, and so it r for radius.


{{{dA/dt=pi*2r*(dr/dt)}}},  and Chain Rule is used.


Description gives  {{{system(dr/dt=25,r=100,dA/dt=FindThisValue)}}}.


{{{highlight(dA/dt=pi*2*100*25)}}}



{{{500*pi}}}