Fuction proof problems

1. Feb 15, 2007

zaczhou

if f(y) is one to one, and f(g(x)) is one to one, is g(x) one to one?
if g(x) is one to one, and f(g(x)) is one to one, is f(y) one to one?
if g(x) and f(g(x)) are onto, is f(y) is also onto?
if f(y) and f(g(x)) are onto, is g(x) is also onto?

2. Feb 15, 2007

cristo

Staff Emeritus
Well, what do you think? You must show your work before we can help you. Do you know the definitions of one-to-one, and onto functions?