Find the range. ① y = 2sinxcos ^ 2x / 1 + SiNx; ② y = Tan ^ 2x - TaNx + 1 / Tan ^ 2x + TaNx + 1

Find the range. ① y = 2sinxcos ^ 2x / 1 + SiNx; ② y = Tan ^ 2x - TaNx + 1 / Tan ^ 2x + TaNx + 1

① Y = 2sinxcos ^ 2x (1-sinx) / (1 + SiNx) (1-sinx) = 2sinx (1-sinx), then the formula is y = - 2 [SiNx + (1 / 2)] ^ 2 + (1 / 2) from the image, y ∈ [- 4,1 / 2] ② y = 1 - [2tanx / (Tan ^ 2x + TaNx + 1)] = 1 - {2 / [TaNx + (1 / TaNx) + 1]} ∵ TaNx + (1 / TaNx) ≥ 2 ∩ y ∈ [1 / 3,1)