Question

Find the rate of change of the area of a circle with respect to its radius
r
when
(a)
r
= 3 cm
(b)
r
= 4 cm

Answer 1

@terenzreignz

Answer 2

\[\huge A = \pi r^2\]\[\huge \frac{dA}{dr}=2\pi r\]
and just plug in.

Answer 3

Thankyou Sir