sin(α+4/π)+sin(α-4/π)=3/根号下2

sin(α+4/π)+sin(α-4/π)=3/根号下2
sin(α+4/π)+sin(α-4/π)=3/根号下2

sin(α+4/π)+sin(α-4/π)=3/根号下2
sin(α+π/4)+sin(α-π/4)=3/√2
sin(α+π/4)+sin(α+π/4-π/2)=3/√2
sin(α+π/4)-cos(α+π/4)=3/√2
√2sin(α+π/4-π/4)=3/√2
sinα=3/2
显然不成立

y=cos²x+sinxcosx
=(1+cos2x)/2+1/2*sin2x
=(1/2)(sin2x+cos2x)+1/2
=(√2/2)(√2/2*sin2x+√2/2cos2x)+1/2
=(√2/2)(sin2xcosπ/4+cos2xsinπ/4)+1/2
=(√2/2)sin(2x+π/4)+1/2
T=2π/2=π