求证cos(3π/2+α)=sinα
求证cos(3π/2+α)=sinα
求证(1+sinα+cosα+2sincosα)/(1+sinα+cosα)=sinα+cosα
求证:2sinα+sin2α=2sin^3α/(1-cosα)
求证sin^2α+cosαcos(π/3+α)-sin^(π/6-α)的值与α无关
求证:1-2sinαcosα/cos²α-sin²α=tan(π/4-α)
求证(1-2sinαcosα)/(cos²α-sin²α)=tan(π/4-α)
求证:(1-sinα+cosα)/(1+sinα+cosα)=tan(π/4-α/2)
求证sin^2α+sin^2β-sin^2αsin^2β+cos^2cos^2β=1
求证:tanα/2=1-cosα/sinα=sinα/1+cosα
求证:sin2α/(1+2sinα+cosα)=sinα+cosα-1
求证:2(1+sinα)(1+cosα)=(1+sinα+cosα)^2
求证:2(1-sinα)(1+cosα)=(1-sinα+cosα)²