急!求函数fx=sin(2x-π/4)-2根号2sin²x的单调递减区间及对称轴

问题描述:

急!求函数fx=sin(2x-π/4)-2根号2sin²x的单调递减区间及对称轴

fx=sin(2x-π/4)-2√2sin²x=√2/2sin2x-√2/2cos2x-√2(1-cos2x)=√2/2sin2x+√2/2cos2x-√2=sin(2x+π/4)-√2
2kπ+π/2