已知3sinθ=cosθ-1,则tanθ/2的值是
已知3sinθ=cosθ-1,则tan(θ/2)的值是,
人气:221 ℃ 时间:2020-07-11 17:26:49
解答
3sin(θ)=cos(θ)-16sin(θ/2)cos(θ/2)=1-2sin²(θ/2)cos(θ/2)-1∴ sin²(θ/2)+3sin(θ/2)cos(θ/2)=0∴ sin(θ/2)*[sin(θ/2)+3cos(θ/2)]=0∴ sin(θ/2)=0或sin(θ/2)+3cos(θ/2)=0∴ tan(θ/2)=sin(...
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