Упростить 1) sin2A/cos^2A-sin^2A 2) cos2A+sin^2A 3) cos36*+sin^2(18*)/cos^2(18*)

1) [latex] \frac{sin2 \alpha }{cos^2 \alpha -sin^2 \alpha } [/latex] = [latex] \frac{sin2 \alpha }{cos2 \alpha } [/latex] = tg2α 2) cos2α+sin²α=cos²α-sin²α+sin²α=cos²α 3) [latex] \frac{cos36+sin^2 18}{cos^218} = \frac{cos 36+1-cos^218}{cos^2 18} = \frac{2cos^218-1+1-cos^218}{cos^218} = \frac{cos^218}{cos^218} = 1[/latex]