f(x)=2sin(x π/4)【cos(x π/4 π/6)】
=2sin(x π/4)【√3/2cos(x π/4)-1/2sin(x π/4)】
=√3sin(x π/4)cos(x π/4)-【sin( π/4)】^2
=√3/2sin(2x π/2) 1/2cos(2x π/2)-1/2
=√3/2cos2x-1/2sin2x-1/2
=cos(2x π/6)-1/2
值域为【-3/2,1/2】
最小正周期T=π
f(x)=2sin(x π/4)【cos(x π/4 π/6)】
=2sin(x π/4)【√3/2cos(x π/4)-1/2sin(x π/4)】
=√3sin(x π/4)cos(x π/4)-【sin( π/4)】^2
=√3/2sin(2x π/2) 1/2cos(2x π/2)-1/2
=√3/2cos2x-1/2sin2x-1/2
=cos(2x π/6)-1/2
值域为【-3/2,1/2】
最小正周期T=π