Consider the following function. f(x) = 5x3 + 15x + 2 (a) Find the critical numbers off. (Enter your answers as a comma-separated list.) X: X (b) Find the open intervals on which the function is increasing or decreasing. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) increasing X decreasing X (c) Apply the First Derivative Test to identify the relative extremum. (If an answer does not exist, enter DNE.) ( x) i x) relative maximum (x, y) relative minimum (x, y) Consider the following function. f(x) = x1/5 + 4 (a) Find the critical numbers of F. (Enter your answers as a comma-separated list.) X: X (b) Find the open intervals on which the function is increasing or decreasing. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) increasing X decreasing DNE Consider the following function. f(X) = (X 905" (a) Find the critical numbers of f. (Enter your answers as a comma-separated list.) X: X (b) Find the open intervals on which the function is increasing or decreasing. (Enter your answers using interval notation. If an answer does not exist, enter DNE.) increasing X decreasing X (c) Apply the First Derivative Test to identify all relative extrema. (If an answer does not exist, enter DNE.) relative maximum (X, y) = ( DNE ) J relative minimum (x, y) = ( ) X