The function f (x) is graphed below. In two or more complete sentences, describe how to find the interval (s) where the function is decreasing and how interval notation is used to express the interval (s). In your final answer, include the interval in which the function is decreasing.

The function is decreasing wherever the slope is negative (y decreasing as x increasing). Interval notation is the x-value range where y is decreasing inside round and square brackets. Unfilled dots use round (or), and filled dots use square [ or ]. Round means either greater/less (but not equal) to x and square means either greater/less or equal to x.

From left to right on the graph:

1st decreasing interval: Solid dot at x=-8 to unfilled dot at x=-5, so 1st decreasing interval is [-8, - 5)

2nd decreasing interval: Solid dot at x=4 to unfilled dot at x=8, so interval is [4, 8)

To join multiple intervals, insert U between the intervals, so f (x) decreases on:

[-8, - 5) U [4, 8)