Fuction proof problems

[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?

 

[cristo]

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?