(1 point) f(z) = 5cosI, on (-27, 27) a) Find the first and second derivatives. f(I) = f" (I) = b) Identify the graph that displays f in blue and f" in red.|? v A. .ah C. CASH D. c) Using the graphs of f and f", indicate where f is concave up and concave down. Give your answer in the form of an interval. NOTE: When using interval notation in WeBWork, remember that: You use 'INF for co and '-INF for -Do. And use 'U' for the union symbol. Enter DNE if an answer does not exist. f is concave up on f is concave down on