Answer
$$\frac{1}{2}\cot (3-2 x)+c$$
Work Step by Step
Given $$\int \csc ^{2}(3-2 x) d x$$
Let $$ u=3-2x\ \ \Rightarrow \ \ du=-2dx$$
Then
\begin{align*}
\int \csc ^{2}(3-2 x) d x&=\frac{1}{2} \int\left(-\csc ^{2} u\right) d u\\
&=\frac{1}{2}\cot u+c\\
&=\frac{1}{2}\cot (3-2 x)+c
\end{align*}