Determine the intervals on which the function is increasing, decreasing, and constant

Step-by-step explanation:

In general, wherever a function is tending from the upper left to the lower right, it is decreasing; wherever a function is tending from the lower left to the upper right it is increasing.  Constant functions are horizontal lines.

Our function is tending from upper left to lower right on negative infinity to an x-value of -4.  Then it runs as a horizontal line from x values of -4 to +4.  Then it tends from lower left to upper right from +4 to infinity.