Let f: A?B and g:B?C be maps.
(A) If f and g are both one-to-onefunctions, show that g?f is one-to-one.
(B) If g?f is onto, show that g isonto.
(C) If g?f is one-to-one, show that fis one-to-one.
(D) If g?f is one-to-one and f is onto,show that g is one-to-one.
(E) If g?f is onto and g is one-to-one,show that f is onto.
(Abstract Algebra)
