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# quick question i think watch

1. V=(4/3)Pi*r3
find the average rate of change of V as r changes from 5 to 6 cm
2. dV/dr when r = 5.5?
3. (Original post by realicetic)
V=(4/3)Pi*r3
find the average rate of change of V as r changes from 5 to 6 cm
V = (4/3)πr³
dV/dr = 4πr²

sub (r = 5) .... 4π(5)² = 100π cm³
sub (r = 6) .... 4π(6)² = 144π cm³

Average rate of change ... ½[144π + 100π] = 122π cm³

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Updated: November 12, 2005
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