化解sin^2αsin^2β+cos^2αcos^2β-1/2cos2αcos2β
化解sin^2αsin^2β+cos^2αcos^2β-1/2cos2αcos2β
化简:sin^2αsin^2β+cos^2αcos^2β-1/2cos2αcos2β
化简(sinα)^2*(sinβ)^2+(cosα)^2(cosβ)^2-1/2cos2αcos2β
化简sinα^2sinβ^2+cos^2cosβ^2-1/2cos2αcos2β
Sin²αSin²β+Cos²αCos²β-1/2Cos2αCos2β
化简:sin²αsin²β+cos²αcos²β-1/2cos2αcos2β
sin²α*sin²β+cos²α*cos²β-1/2cos2αcos2β
化简:sin²αsin²β+cos²αcos²β—1/2cos2αcos2β
sin²αsin²β+cos²αcos²β-【(1/2)*cos2αcos2β】
化简 sin²αsin²β+cos²αcos²β-1/2(cos2αcos2β)
2sinα=sinθ+cosθ,sin²β==sinθcosθ.求证cos2β=2cos2α=2cos
已知sinθ+cosθ=2sinα,sinθcosθ=(sinβ)^2,求证4(cos2α)^2=(cos2β)^2