Answer to Question #77239 in Discrete Mathematics for muhammad hassan

Question

Q : 5). If f is function from A to B and g is function B to C and both f and g are onto.
Show that go f is also onto. Is go f one-to-one if both f and g are one-to-one.


Q : 6) Let f, g and h: R → R be defined by (R is the set of real numbers)
f(x) = x + 2, g(x) = (1 + x2)
-1, h(x) = 3.
Compute f -1g(x) and hf (g f -1) (hf(x)).