l. (a) Graph the function f(.r) = 4 :32. (Then, use the graph to answer part (b) and (c)) (1)) Identify the point (a, f(a)) at which the function has a tangent line with zero slope. (c) Consider the point {a,f(a)) found in part (b). Is it true that the secant line between (ah, f(ah)) and (a + h, f(a, + h)) has slope zero for any value of h 0'? Explain