Some stretches of the graph go uphill and others downhill, so circle the run of x values that share one trend as a single monotonic interval.
Module goal. Learn to capture a function's rise and fall, symmetry, and high and low points from both the graph and the symbols, getting ready to analyze linear functions
eastmath.com · 20.6 Reading a Function's Behavior off Its Graph · 20.6.2 Intervals of Increase and Decrease