2sin²α·cos²α + 2tg⁴α·cos⁴α сократить
2sin^2(a)*cos^2(a) + 2sin^4(a)*cos^4(a)/cos^4(a) = 2sin^2(a)*cos^2(a) + 2sin^4(a) = 2sin^2(a)*cos^2(a) + 2sin^2(a)*(1 - cos^2(a)) = 2sin^2(a)*cos^2(a) + 2sin^2(a) - 2sin^2(a)*cos^2(a) = 2sin^2(a)