解由f(x)=√3cos2x-sin2x
=2(√3/2cos2x-1/2sin2x)
=2(cosπ/6cos2x-sinπ/6sin2x)
=2cos(2x+π/6)
故当2kπ+π≤2x+π/6≤2kπ+2π,k属于Z时,y=f(x)是增函数
即当kπ+5/12π≤x≤kπ+11/12π,k属于Z时,y=f(x)是增函数
即函数f(x)=√3cos2x-sin2x的单调递增区间是[kπ+5/12π,kπ+11/12π],k属于Z.
解由f(x)=√3cos2x-sin2x
=2(√3/2cos2x-1/2sin2x)
=2(cosπ/6cos2x-sinπ/6sin2x)
=2cos(2x+π/6)
故当2kπ+π≤2x+π/6≤2kπ+2π,k属于Z时,y=f(x)是增函数
即当kπ+5/12π≤x≤kπ+11/12π,k属于Z时,y=f(x)是增函数
即函数f(x)=√3cos2x-sin2x的单调递增区间是[kπ+5/12π,kπ+11/12π],k属于Z.