问题标题:
数学题三角函数已知2sin(3π+θ)=cos(π+θ),求2sin^2θ+3sinθcosθ-cos^2θ
问题描述:
数学题三角函数
已知2sin(3π+θ)=cos(π+θ),求2sin^2θ+3sinθcosθ-cos^2θ
郭建星回答:
2sin(3π+θ)=cos(π+θ)2sinθ=cosθtanθ=1/22sin^2θ+3sinθcosθ-cos^2θ2sin^2θ+3sinθcosθ-cos^2θ___________________________=____________________________=1...
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