Question

Leaking oil forms a circle on the ground below that is growing at a rate of ten squareinches per minute. What is the rate of change of the radius of the circle when the radiusis 22 inches?

Answer 1

Answer:
`(5)/(22\pi)` inches per minute

Explanation:

`A=\pi r^2\\\\(dA)/(dt)=2\pi r (dr)/(dt)\\\\10=2 \pi \cdot 22 (dr)/(dt)\\\\(dr)/(dt)=(10)/(44\pi)=(5)/(22\pi)`