Question

A rock is dropped in a pond, causing circular ripples. The radius increased with a rate 1 foot per second. When the radius is 4 feet, the area is increasing by 8π square feet per second.1. True2. False

Answer 1

pi/2

Step-by-step explanation:

on ed

Answer 2

true

Step-by-step explanation:

Area = πr²

Differentiating in respect to r

we get,

dA/dr = 2πr

using chain rule,

`(dA)/(dt) = (dA)/(dr) .(dr)/(dt) = 2\pi (dr)/(dt)`

since r = 4feet

so ,

2π(4) = 8π