Question

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

Answer 1

$frac{Sin^{2}(pi+alpha)+Sin^{2}(frac{pi }{2}+alpha)}{Cos(frac{3pi}{2}+alpha)}*Ctg(frac{3pi}{2}-alpha)=frac{Sin^{2}alpha+Cos^{2}alpha}{Sinalpha}*tgalpha=frac{1}{Sinalpha}*frac{Sinalpha}{Cosalpha}=frac{1}{Cosalpha}$