)=−3sin(x)cos(x)on(− a) find the critical numbers of (separate multiple answers by commas.) b) determine the intervals on which is increasing and decreasing. is increasing on: is decreasing on: c) use the first derivative test to determine whether each critical point is a relative maximum, minimum, or neither. relative maxima occur at x= (separate multiple answers by commas.) relative minima occur at x= (separate multiple answers by commas.)