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求证tanθ+secθ=tan(θ/2+π/4)
人气:249 ℃ 时间:2020-09-03 07:16:53
解答
tanθ+secθ=sinθ/cosθ+1/cosθ=(sinθ+1)/cosθ=[cos(π/2 -θ)+1]/sin(π/2 -θ)=2cos²(π/4 -θ/2)/[2sin(π/4 -θ/2)cos(π/4 -θ/2)]=cos(π/4 -θ/2)/sin(π/4 -θ/2)=cot(π/4 -θ/2)=tan[π/2-(π/4 ...
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