Question

sin^2 альфа+tg^2 альфа+cos^2 альфа=1cos^2альфа

Answer 1

$sin^2 alpha +tg^2 alpha +cos^2 alpha =(sin^2 alpha +cos^2 alpha )+tg^2 alpha =\\=1+ frac{sin^2 alpha }{cos^2 alpha }=frac{cos^2 alpha s+in^2 alpha }{cos^2 alpha } } = frac{1}{cos^2 alpha }$