f(x)=2sin^2(π/4+x)-√3cos2x-1
=1-cos(π/2+2x)-√3cos2x-1
=-cos(π/2+2x)-√3cos2x
=sin2x-√3cos2x
=2(1/2sin2x-√3/2cos2x)
=2sin(2x-π/3)
T=2π/2=π
x∈[π/4, π/2],
所以(2x-π/3)∈[π/6, 2π/3],
那么2sin(2x-π/3)∈[1, 2],
│f(x)-m│
f(x)=2sin^2(π/4+x)-√3cos2x-1
=1-cos(π/2+2x)-√3cos2x-1
=-cos(π/2+2x)-√3cos2x
=sin2x-√3cos2x
=2(1/2sin2x-√3/2cos2x)
=2sin(2x-π/3)
T=2π/2=π
x∈[π/4, π/2],
所以(2x-π/3)∈[π/6, 2π/3],
那么2sin(2x-π/3)∈[1, 2],
│f(x)-m│