When a stone fell in a lake, a circular wave was formed and kept expanding regularly keeping its circular shape. Determine the rate of change of the wave’s area
when the radius is cm.
The area of the circular wave formed when the radius is is
The rate of change of the area when is given by
First, find expressions for and .
Now substitute both expressions into the rate of change function.
Finally, substitute the value of .
Therefore, the rate of change of the wave's area when the radius is cm is .