解法一：sinx=cosx那么sinx-cosx=0√2(sinx*√2/2-cosx*√2/2)=0√2[sinx*sin(π/4)-cosx*cos(π/4)]=0√2sin(x-π/4)=0那么x-π/4=kπ (k=0,±1,±2,±3……)即:x=(k+1/4)π解法二:sinx=cosx当cosx≠0时,sinx/cosx=...