Let G be any directed graph. We say that two nodes s and t of G are strongly connected in G if there is a directed path from s to t as well as there is a directed path from t to s. Let sRct denote the property that s and t are strongly connected in G. (a) (10 points) Show that Rc is an equivalence relation. (b) (15 points) Show the language (G, s, t) s and t are strongly connected in G is in class P