Is it true that if g is one-to-one then f o g must be one-to-one? Give a proof or a counterexample.

1 Answer
Jul 25, 2018

It is not true in general that if g is one-to-one then f \circ g must be one-to-one.

Explanation:

This is not true in general.

Notice that the identity function g(x)=x is a one-to-one function. If f(x) is any function that is not one-to-one, f(g(x)) = f(x) and is therefore also not one-to-one.