Calculus
posted by Michael .
V=4/3 pi r ^3 is the formula for the volume of a sphere. Find dV for a sphere if the radius of 10" is increased by .1"
Please help. I have no idea how to do this problem!

dV/dr = 4π r^2
dV = (4πr^2)(dr)
sub in r = 10 and dr = .1
dV = 4π(100)(.1) = 40π