tanθ/(1+〖tan〗^2 θ)≡sinθcosθ

tanθ/(1+〖tan〗^2 θ)≡sinθcosθ
(1-(〖tan〗^(2 ) 60)/sin30)〖cos〗^245
sinθ=7/25 find the value of 3tanθ-1/cosθ by using 勾股定理
(tanθ/cosθ+sinθ/(〖cos〗^2 θ ))×〖cos〗^2θ
Cos(40-3θ)=sin(7θ+2)
If tanA=5/3 find the value of 4sinA/(3sinA-cosA) by using 三角恒等式
看不惯可以看图片