In many cases, factoring an expression can make it easier to evaluate as in the following...

In many cases, factoring an expression can make it easier to evaluate as in the following applications.

Conical shells: The volume of a conical shell (like the shell of an ice cream cone) is given by the formula , where R is the outer radius and r is the inner radius of the cone. Write the formula in completely factored form, then find the volume of a shell when R = 5.1 cm, r = 4.9 cm, and h = 9 cm. Answer in exact form and in approximate form rounded to the nearest tenth.