sin^2+cos^2a=tan^2+1 大家都来求证阿
求证:tan a/2=(1-cos)/sin a=sin a/(cos a+1)
求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos
求证[1]1-2sin acos a/cos²a -sin²a =1-tan a/1+tan a.[
求证:tan(α/2)=(sin α)/(1+cos α)
求证:sin^2A+cos^2A+sinAcosA/sin^2A+cos^2A=tan^2A+1+tanA/tan^2A
求证1/(sin^2)a+1/(cos^2)a-1/(tan^2)a=2+(tan^2)a
求证:tanα/2=1-cosα/sinα=sinα/1+cosα
求证1+2sinαcosα/sin^2α-cos^2α=tanα+1/tanα-1
为什么 tan a +1/tan a=sin^2 a +cos^2 a/(sina cos a)
求证 sin^2αtanα+cos^2α/tanα+2sinαcosα=tanα+1/tanα
求证:(1+sinα)/cosα=(1+tanα/2)/(1-tanα/2)
证明tan a/2=sin a/(1+cos a)