Produce graphs of $f$ that reveal all the important

aspects of the curve. In particular, you should use graphs of $f^{\prime}$

and $f^{\prime \prime}$ to estimate the intervals of increase and decrease,

extreme values, intervals of concavity, and inflection points.

$$f(x)=6 \sin x+\cot x, \quad-\pi \leqslant x \leqslant \pi$$