3. (a) Suppose that f is a function satisfying | f (x)| 5 |x| for all x. Show that f is continuous at 0. (Notice that f (0) must equal 0.) (b) Give an example of such a function f which is not continuous at any a a 0. (c) Suppose that g is continuous at 0 and 3(0) = 0, and | f (x)| 5 |g(x)|. Prove that f is continuous at 0