求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值 化简:(sinθ+sin3θ+sin5θ)/化简:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)=求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/04 15:03:06
求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值 化简:(sinθ+sin3θ+sin5θ)/化简:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)=求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值

求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值 化简:(sinθ+sin3θ+sin5θ)/化简:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)=求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值
求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值 化简:(sinθ+sin3θ+sin5θ)/
化简:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)=
求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值

求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值 化简:(sinθ+sin3θ+sin5θ)/化简:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)=求sin²αsin²β+cos²αcos²β-1/2cos2αcos2β的值
1.sin²αsin²β+cos²αcos²β-1/2cos2αcos2β
=(1-cos^2a)(1-cos^2b)+cos^2a*cos^2b-1/2cos2αcos2β
=1-cos^2a-cos^2b+2cos^2a*cos^2b-1/2cos2αcos2β
=1-(1+cos2a)/2-(1+cos2b)/2+2*(1+cos2a)/2*(1+cos2b)/2-1/2cos2αcos2β
=-cos2a/2-cos2b/2+1/2+cos2a/2+cos2b/2+1/2cos2αcos2β-1/2cos2αcos2β
1/2
2:(sinθ+sin3θ+sin5θ)/(cosθ+cos3θ+cos5θ)
=(sin(3θ-2θ)+sin3θ+sin(3θ+2θ))/(cos(3θ-2θ)+cos3θ+cos(3θ+2θ))
=(2sin3θcos2θ+sin3θ)/(2cos3θcos2θ+cos3θ)
=sin3θ(2cos2θ+1)/cos3θ(2cos2+1)
=tan3θ