13) Let f (x) = x2 + 1 and g(x) = x + 2 are relations on the set of real numbers.

(a) Decide whether f(x) and g(x) are function, if so, state whether they are injection,

surjection or bijection. (4 marks)

(b) Does either f (x) or g(x) have an inverse? If so, find the inverse. (3 marks)

(c) Find f g and g f . (6 marks)