यदि \(y(\alpha)=\sqrt{2\left(\frac{\tan \alpha+\cot \alpha}{1+\tan ^2 \alpha}\right)+\frac{1}{\sin ^2 \alpha}}\) है जहाँ \(\alpha \in\left(\frac{3 \pi}{4}, \pi\right)\) है, तो \(\frac{d y}{d \alpha}\ \rm at\ \alpha=\frac{5 \pi}{6}\) है
1
\(-\frac{1}{4}\)
2
\(\frac{4}{3}\)
3
\(4\)
4
\(-4\)