y=cos^2x-sin^2-√3cos(3π/2+2x)+1 =cos2x-√3sin2x+1 =2cos(2x+π/3)+1当2kπ+π/2≤2x+π/3≤2kπ+3π/2时,函数单调递减2kπ+π/2≤2x+π/3≤2kπ+3π/22kπ+π/6≤2x≤2kπ+7π/6kπ+π/12≤x≤kπ+7π/12所以单调递减区间:[kπ+π/12,kπ+7π/12],k∈Z最大值:ymax=3最小值:ymin=-1