Question:
Mark $(\sqrt{)}$ against the correct answer in each of the following:
$\int \cot ^{2} x d x=?$
A. $-\cot x-x+C$
B. $\cot \mathrm{x}-\mathrm{x}+\mathrm{C}$
C. $-\cot x+x+C$
D. $\cot x+x+C$
Solution:
Given:
$\int \cot ^{2} x d x=\int\left((\csc x)^{2}-1\right) d x$
$=-\cot x-x+c$