A circular puddle’s radius is increasing at a rate of when the radius is

MATHEMATICS · Subjective · AP · Calculus AB · Contextual Applications of Differentiation · Contextual Applications of Differentiation

Problem

A circular puddle’s radius is increasing at a rate of

3\text{ in/min}

when the radius is

20\text{ in}

. Determine the rate at which the area of the puddle is changing at that instant. Express your answer in square inches per minute.