化简:(sinα-cosα)^2+sin4α/2cos2α 化简:sin^2x+sin^2(x+2π/3)+sin^2(
来源:学生作业帮 编辑:大师作文网作业帮 分类:数学作业 时间:2024/09/22 04:18:25
化简:(sinα-cosα)^2+sin4α/2cos2α 化简:sin^2x+sin^2(x+2π/3)+sin^2(x-2π/3)
(sinα-cosα)²+sin4α/2cos2α
=1-2sinαcosα+2sin2αcos2α/2cos2α
=1-sin2α+sin2α
=1
sin²x+sin²(x+2π/3)+sin²(x-2π/3)
=sin²x+sin²(x+π-π/3)+sin²(x+π/3-π)
=sin²x+sin²(π+x-π/3)+sin²(-π+x+π/3)
=sin²x+sin²(x-π/3)+sin²(x+π/3)
=sin²x+(1/4)sin²x-(√3/2)sinxcosx+(3/4)cos²x+(1/4)sin²x+(√3/2)sinxcosx+(3/4)cos²x
=sin²x+(1/2)sin²x+(3/2)cos²x
=(3/2)sin²x+(3/2)cos²x
=(3/2)(sin²x+cos²x)
=3/2
=1-2sinαcosα+2sin2αcos2α/2cos2α
=1-sin2α+sin2α
=1
sin²x+sin²(x+2π/3)+sin²(x-2π/3)
=sin²x+sin²(x+π-π/3)+sin²(x+π/3-π)
=sin²x+sin²(π+x-π/3)+sin²(-π+x+π/3)
=sin²x+sin²(x-π/3)+sin²(x+π/3)
=sin²x+(1/4)sin²x-(√3/2)sinxcosx+(3/4)cos²x+(1/4)sin²x+(√3/2)sinxcosx+(3/4)cos²x
=sin²x+(1/2)sin²x+(3/2)cos²x
=(3/2)sin²x+(3/2)cos²x
=(3/2)(sin²x+cos²x)
=3/2
化简:(sinα-cosα)^2+sin4α/2cos2α 化简:sin^2x+sin^2(x+2π/3)+sin^2(
化简(sinα-cosα)^2-1/-cos2α
化简(sin2α+sinα)/(2cos2α+2sin^2α+cosα)
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
化简:sin²αsin²β+cos²αcos²β-1/2cos2αcos2β
化简:sin²αsin²β+cos²αcos²β—1/2cos2αcos2β
化简 sin²αsin²β+cos²αcos²β-1/2(cos2αcos2β)
(2sinα+cosα)/(sinα-3cosα)=-5 求cos2α
已知sinα -2cosα=0,求(1)sinαcosα的值(2)sin4α+cos2α
2sinα=sinθ+cosθ,sin²β==sinθcosθ.求证cos2β=2cos2α=2cos