tanΘ/2-1/(tanΘ/2)化简

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tanΘ/2-1/(tanΘ/2)化简

tanΘ/2-1/(tanΘ/2)化简
tanΘ/2-1/(tanΘ/2)化简

tanΘ/2-1/(tanΘ/2)化简
∵tanθ=2tan(θ/2)/[1-tan²(θ/2)]
∴1-tan²(θ/2)=2tan(θ/2)/tanθ
∴原式=[tan²(θ/2)-1]/tan(θ/2)
=-2tan(θ/2)/tanθtan(θ/2)
=-2/tanθ
=-2cotθ

tanΘ/2-1/(tanΘ/2)=(sinΘ/2)/(cosΘ/2)-(cosΘ/2)/(sinΘ/2)
=[(sinΘ/2)^2-(cosΘ/2)^2]/(sinΘ/2)*(cosΘ/2)
=-cosΘ/(1/2sinΘ)
=-2cotΘ

注:你的那个角啊,我用x表示可以吗?
原式=[tan(x/2)]-[1/tan(x/2)]
={sin(x/2)/cos(x/2)]-[cos(x/2)/sin(x/2)]
=[sin²(x/2)-cos²(x/2)]/[sin(x/2)cos(x/2)]
=(-2cosx)/(sinx)
=-2cotx.