Answer
$$\int \frac{\cot ^{3} t}{\csc t} d t =-\csc t-\sin t+c$$
Work Step by Step
$$
\int \frac{\cot ^{3} t}{\csc t} d t
$$
Since
\begin{align*}
\int \frac{\cot ^{3} t}{\csc t} d t&= \int \frac{(\csc ^{2} t-1)\cot t}{\csc t} d t\\
&=\int (\csc t\cot t-\cos t)dt\\
&=-\csc t-\sin t+c
\end{align*}