Question

пожалуйста помогите очень нужна помощь

Answer 1

cos^4 (α) + sin^2 (α) cos^2 (α) = cos^2 (α) (cos^2 (α) + sin^2 (α)) = cos^2 (α) = (1 + cos2α)/2

sin^2 (α) cos^2 (α) + sin^4 (α)/sin^2 (α) cos^2 (α) + cos^4 (α) - 1 = sin^2 (α) × (cos^2 (α) + sin^2 (α))/cos^2 (α) - 1 = - sin^2 (α)/sin^2 (α) = -1

(sin(α) - cos(α))^2 - 1/sin^2(α) - cos^2(α) -1 = 1 - sin2α - 1/-2cos^2(α) = -2sin(α)cos(α)/-2cos^2(α) = - sinα/-cosα = tgα