Chapter 10.3, Problem 7E

7. Prove the following properties:

a. If $f$ and $\text{g}$ are even functions, then so is the $f\text{g}$.

b. If $f$ and $\text{g}$ are odd functions, then $f\text{g}$ is an even function.

c. If $f$ is an even function and g is an odd function, then $f\text{g}$ is an odd function.