Преобразуйте выражение 2cos^2 a-1/1-2sin^2 a - sin^2 a

Ответ:

cos^2(a)

Пошаговое объяснение:

2cos^2(a) - 1/1-2sin^2(a) - sin^2(a) = 2cos^2(a) - sin^2(a) - cos^2(a)/sin^2(a) + cos^2(a) - 2sin^2(a) - sin^2(a) =  cos^2(a) - sin^2(a)/cos^2(a) - sin^2(a) - sin^2(a) = 1-sin^2(a) = cos^2(a)

sin^2(a) + cos^2(a) = 1