Chapter 11: Problem 985
\(\mathrm{I}=\int \cot ^{2} \mathrm{x} \cdot \operatorname{cosec}^{4} \mathrm{xdx}=-\left(\mathrm{k}^{3} / 3\right)-\left(\mathrm{k}^{5} / 5\right)+\mathrm{c}\) then \(\mathrm{k}\) is (a) \(\sin x \cdot \cos x\) (b) \(\cot x\) (c) \(-\cot x\) (d) \(\tan \mathrm{x}\)