1. (4+4 points) Let f:ST and g:US be functions, and consider the composition h=fg. So h is a function from U to T, with h(u):=f(g(u)). Determine whether the following statements are true or false. If true, give a proof; if false, give a counterexample. (a) If h is injective, then g is injective. (b) If h is injective, then f is injective