Consider the function f(x)=3x-3x-2 and complete parts (a) through (c). (a) Find f(a + h); (b) Find f(a+h); h (c) Find the instantaneous rate of change of f when a = 6. (a) f(a+h)=3a+3h2+3ah - 3a-3h-2 (Simplify your answer. Do not factor.) (b) f(a + h)-f(a) h = (Simplify your answer. Do not factor.) (c) The instantaneous rate of change of f when a = 6 is (Simplify your answer.)