注釋：此題有可能是書寫錯(cuò)誤,可能是后面的括號(hào)寫掉了.
我想原題應(yīng)該是[2（cosα）^2-1]/[2tan(π/4-α)*[sin(π/4+α)]^2]化簡.
它的化簡結(jié)果是1.解題過程如下：
[2（cosα）^2-1]/[2tan(π/4-α)*[sin(π/4+α)]^2]
=cos（2α）/2*（cos（π/4-α）/sin(π/4-α))*(2/(1-cos(π/2+2α))
=cos（2α）/2*（1+cos（π/2-2α）/sin(π/2-2α))*(2/(1+sin2α))
=(cos（2α）/(1+sin2α))*((1+sin2α)/cos（2α）)
=1