Please write down the answers, don't just attach the results. thank you!

PREVIOUS ANSWERS LARCALC9 3.3.021. Consider the following function. f(x) = 4x3 + 6.12 - 24.x (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. (Select all that apply.) Increasing: V (-00, -2) D (- 2, 1) (1, 00 ) O (-00, 00 ) Decreasing: O (-00, - 2) (-2, 1) O (1, 00) 1 ( -00, 00 ) (c) Apply the First Derivative Test to identify the relative extremum. (If an answer does not exist, enter DNE.) relative maximum (x, y) = ( X relative minimum (x, y) = ( x ) (d) Use a graphing utility to confirm your results. Submit