(1 point) For the function f(x)-3x +2sin(x), find all intervals where the function is increasing f is increasing on (Give your answer as an interval or a list of intervals, e.g., (-infinity,8] or (1,5),(7,10). Enter none if there are no such intervals.) Similarly, find all intervals where the function is decreasing: f is decreasing on (Give your answer as an interval or a list of intervals, e.g, (-infinity,8] or (1,5),(7,10). Enter none if there are no such intervals.) Finally, find all critical points in the graph of f (x) (enter z values as a comma-separated list, or none if there are no critical points):
