Hello mates, I need help with this,

Assume that:

f(x) = $\displaystyle \sqrt \frac{x-1}{x+1} $

a. Find the domain of f

b. If f(a) = 2, find f(–a), –f(a), f (1/a), and 1/f(a).

c. Give an example of a function whose domain equals (–1, 1) and whose range equals the range of f.

d. Sketch the graph of a function whose domain equals the domain of f and whose range equals {–1, 1}.