The slope of the function is most positive either side of x=0 and x=2π.
On the interval [0, π/4], the average slope is [tex]\dfrac{(\frac{\sqrt{2}}{2})}{(\frac{\pi}{4})} = \dfrac{2\sqrt{2}}{\pi}[/tex]
On the interval [7π/4, 9π/4], the average slope is [tex]\dfrac{(\frac{\sqrt{2}}{2}-\frac{-\sqrt{2}}{2})}{(\frac{9\pi}{4}-\frac{7\pi}{4})}=\dfrac{2\sqrt{2}}{\pi}[/tex]
The average rate of change is highest on the intervals [0, π/4] and [7π/4, 9π/4].
