Thank you to every one for their help. I understand it a lot better now.

krtxmrtz or anyone can you just go through how to get the h^-1(x) which you got as 2 / (x - 1).

Also finally just need help in how to get the inverse of f(x) = 1 / (2x - 5), f(x) = x^2 + 2x + 5, f(x) = sqrt(4 - x^2) and f(x) = (2x - 5)^3 + 3. Was able to get the inverse of most of the questions I required but these gave me some trouble.