Mark the correct alternative in the following:
The diameter of a circle is increasing at the rate of 1cm/sec. When its radius is π, the rate of increase of its area is

Question

Mark the correct alternative in the following: The diameter of a circle is increasing at the rate of 1cm/sec. When its radius is π, the rate of increase of its area is

Philoid · Accepted Answer

The circumference of a circle, with radius r, is defined as

A(r)=πr² – (1)

Given that r=π cm, , we have to calculate

Differentiating (1) with respect to t, we get

Mark the correct alternative in the following:The diameter of a circle is increasing at the rate of 1cm/sec. When its radius is π, the rate of increase of its area is

Mark the correct alternative in the following:
The diameter of a circle is increasing at the rate of 1cm/sec. When its radius is π, the rate of increase of its area is