求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos
求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos
求证:tanα/2=1-cosα/sinα=sinα/1+cosα
求证:tan a/2=(1-cos)/sin a=sin a/(cos a+1)
求证:tan(α/2)=(sin α)/(1+cos α)
求证sinθ/(1+cosθ)+(1+cosθ)/sinθ=2/sinθ
求证1+2sinαcosα/sin^2α-cos^2α=tanα+1/tanα-1
求证(1+sinα)/(1+sinα+cosα)=1/2(1+(tanα/2))
求证(1+sinα/1-sinα)=(1/cosα+tanα)^2
已知tan∝=2/3,求值:(1)(cos∝-sin∝/cos∝+sin∝)+(cos∝+sin
若θ,α为锐角,且tanθ=(sinα-cosα)/(sinα+cosα)求证sinα-cosα=根号2sinθ
若α β是锐角tanβ=sinα -cosα / sinα + cosα 求证sinα -cosα=根号2sinβ
当α β是锐角tanθ=sinα -cosα / sinα + cosα 求证sinα -cosα=根号2sinθ