Question

$\frac{sin^{2}(\pi+\alpha)+sin^{2}(\frac{\pi }{2}+\alpha)}{cos(\frac{3\pi }{2}+\alpha)}$ · $ctg(\frac{3\pi }{2}-\alpha)$

Answer 1

$\frac{Sin^{2}(\pi+\alpha)+Sin^{2}(\frac{\pi }{2}+\alpha)}{Cos(\frac{3\pi}{2}+\alpha)}*Ctg(\frac{3\pi}{2}-\alpha)=\frac{Sin^{2}\alpha+Cos^{2}\alpha}{Sin\alpha}*tg\alpha=\frac{1}{Sin\alpha}*\frac{Sin\alpha}{Cos\alpha}=\frac{1}{Cos\alpha}$