rate is its area changing when the radius is 5 ft.
<u>Step-by-step explanation:</u>
Here we have , The radius of a circle is increasing at a rate of 3 ft/min. We need to find At what rate is its area changing when the radius is 5 ft. Let's find out:
We know that area of circle = .
⇒
Differentiating both sides w.r.t to time we get :
⇒
⇒ ............(1) {
}
But , According to Question
Putting this value in equation (1):
⇒
⇒
⇒
Therefore , rate is its area changing when the radius is 5 ft.