# HUH?! How to show the area given?

UNDER THE CHAPTER OF DIFFERENTIATION

The diagram shows a hemispherical bowl with a radius of r cm. Water is poured into the bowl at a constant rate.

(a) Show that when the water level in the bowl is h cm, the surface area, A cm^2, of the water in the bowl is given by A = πh(2r - h). (b) If r = 5 and the rate of change in water level is 0.6 cm s^-1, find the rate of change in the surface area when h = 2.

***The answer provided is for question (b).