Question

Тригонометрия. Помогите,пожалуйста. Задание во вложении.

Answer 1

$frac{sin^2 alpha -cos^2 alpha +cos^4 alpha }{cos^2 alpha -sin^2 alpha +sin^4 alpha} = frac{sin^2 alpha -cos^2 alpha (1-cos^2 alpha) }{cos^2 alpha -sin^2 alpha(1-sin^2 alpha)} = frac{sin^2 alpha -cos^2 alpha *sin^2 alpha }{cos^2 alpha -sin^2 alpha*cos^2 alpha } =$$=frac{sin^2 alpha(1 -cos^2 alpha) }{cos^2 alpha(1 -sin^2 alpha) } =frac{sin^2 alpha*sin^2 alpha}{cos^2 alpha*cos^2 alpha } = frac{sin^4 alpha }{cos^4 alpha } =tg^4 alpha$