函数f(x)=(cosx+sinx)/(cosx-sinx)的最小正周期

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f(x)=(cosx+sinx)/(cosx-sinx)
上下绝早陪除cosx
=(1+tanx)/(1-tanx)
=(tanπ/4+tanx)/(1-tanπ/4*tanx)
=tan(x+π/睁扒4)
所以最小并蠢正周期是T=π

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