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The rate of change (in cm2/s) of the total surface area of a hemisphere with respect to radius r at $r=\sqrt[3]{1.331}$ cm is: |
$66 \pi$ $6.6 \pi$ $3.3 \pi$ $4.4 \pi$ |
$6.6 \pi$ |
The correct answer is Option (2) → $6.6 \pi$ TSA of hemisphere $T=3πr^2$ let $\frac{dr}{dt}=1$ $\frac{dT}{dr}=6πr\frac{dr}{dt}$ $=6π×\sqrt[3]{1.331}$ $=6π×1.1$ $=6.6π$ sq. units |
