Help me with part b

Consider the function on the interval (0, 27). Use a graphing utility to confirm your answers for parts (a) and (b). f(x) = x- 2 sin(x) (a) Find the open intervals on which the function is increasing or decreasing. (Enter your answers using interval notation.) a increasing 3' 3 decreasing (0, 5 3 2TE (b) Apply the First Derivative Test to identify the relative extrema. (If an answer does not exist, enter DNE.) 57t relative maximum (x, y) = 3 , 6.97 X relative minimum ( x, y ) = 3' - 0.685 X