求证：（tanx+secx-1）/（tanx-secx+1）=（1+sinx）/cosx
证宴改明： (tanx+secx-1)/(tanx-secx+1) =(sinx-cosx+1)/(sinx+cosx-1) =(sinx-cosx+1)(sinx+cosx+1)/[(sinx+cosx-1)(sinx+cosx+1)] =2sinx(1+sinx)/(2sinxcosx) =(1+sinx)/cosx 故拍凯：(tanx+secx-1)/(tanx-secx+1)=(1+sinx)/cosx。晌贺判