函数y=cos^2(x+π/2﹚的单调增区间是

问题描述:

函数y=cos^2(x+π/2﹚的单调增区间是
答案是(kπ,π/2+kπ)k∈Z

cos^2(x+π/2﹚=(1+cos(2x+π))/2=(1-cos(2x))/2
因为cos(x)的单调增区间是(2k-1)π