I'm just having trouble answering part b. Please explain

Consider the function on the interval (0, 27r). (x) = x - 2 sin x (a) Find the open Intervals on which the function is increasing or decreasing. (Enter your answers using interval notation.) 57t increasing 3' 3 V decreasing (0, 7 ) U ,2TE (b) Apply the First Derivative Test to identify the relative extrema. relative maximum (x, y) = X relative minimum ( x, y) = X