f(x)=√3cos2x+2sin(x+π/2)cos(x+π/2)
=√3cos2x+sin(2x+π)
=√3cos2x-sin2x
=2(√3/2cos2x-1/2sin2x)
=2(sinπ/3cos2x-cosπ/6sin2x)
=2sin(π/3-2x)
单调递增区间：2kπ-π/2