Question

Спростити

cos ^{2} alpha -sin ^{2} alpha /2 sin alpha *cos alpha -ctg2 alpha +1[/tex]

Answer 1

$frac{cos ^{2} alpha -sin ^{2} alpha}{2 sin alpha *cos alpha} -ctg2 alpha +1= frac{cos2 alpha }{sin2 alpha} -ctg2 alpha +1=ctg2 alpha -ctg2 alpha +1=1$