(b) Integrate the f(x, y) over the sample space and set the integral equal to 1. Then solve for c.
(c) Apply the definitions and do the necessary calculations.
(d) Does f(x, y) = f(x) f(y)?
(e) Integrate f(x, y) over an appropriate region of the sample space.
If you need more help, please post all your work and say where you get stuck.