题目

已知3sinθ=cosθ-1,则tanθ/2的值是
已知3sinθ=cosθ-1,则tan(θ/2)的值是,

提问时间：2020-12-11

答案

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(...