Question

$2sin ^{2} *765 x^{0} -tg^{2} frac{33}{4} pi *ctg frac{3}{4} pi =$

Answer 1

$...=2sin^2(4pi +frac{pi}{4})-tg^2(8pi +frac{pi}{4})cdot ctg(pi -frac{pi}{4})=\\=2sin^2frac{pi}{4}-tg^2frac{pi}{4}cdot ctg(-frac{pi}{4})=2cdot (frac{sqrt2}{2})^2-1^2cdot (-1)=1+1=2$