已知函数f(x)=sin2x+cox2x,x属于R.求f(x)的单调递增区间._数学解答

已知函数f(x)=sin2x+cox2x,x属于R.求f(x)的单调递增区间.

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解答

f(x)=sin2x+cos2x
=√2(√2/2*sin2x+√2/2cos2x)
=√2(sin2xcosπ/4+cos2xsinπ/4)
=√2sin(2x+π/4)
"递增则2kπ-π/2