1-2sin^2(x+π/4)+2sin(x+π/8)cos(x+π/8)
=1-sin^2(x+π/4)-sin^2(x+π/4)+sin(2x+π/4)
=cos^2(x+π/4)-sin^2(x+π/4)+sin(2x+π/4)
=cos(2x+π/2)+sin(2x+π/4)
=sin(2x+π/4)-sin2x
所以最小正周期T=2π/2=π
1-2sin^2(x+π/4)+2sin(x+π/8)cos(x+π/8)
=1-sin^2(x+π/4)-sin^2(x+π/4)+sin(2x+π/4)
=cos^2(x+π/4)-sin^2(x+π/4)+sin(2x+π/4)
=cos(2x+π/2)+sin(2x+π/4)
=sin(2x+π/4)-sin2x
所以最小正周期T=2π/2=π