I understand some of the concept but I am having trouble putting down mathematical sentences that look presentable. Help would be appreciated, thanks!
First question:
Let f : R∗ → R with f (x) = e^x + x, where R∗ is the set of all real numbers
different from 0.
i. Determine whether or not f is a one to one function.
ii. Determine whether or not f is an onto function.
Second one:
Let f : A → B and g : B → C be functions. Prove that if f and g are both
one-to-one, then g ◦ f is also one-to-one.