y=sin²+sinxcosx+2
=(1-cos2x)/2+(sin2x)/2+2
=0.5+0.5(sin2x-cos2x)+2
=2.5+0.5*√2[(√2/2)sin2x-(√2/2)cos2x]
=2.5+0.5*√2sin(2x-45) (x∈R)sin(2x-45) [-1,1]
值域
[5/2-√2/2,5/2+√2/2]
y=sin²+sinxcosx+2
=(1-cos2x)/2+(sin2x)/2+2
=0.5+0.5(sin2x-cos2x)+2
=2.5+0.5*√2[(√2/2)sin2x-(√2/2)cos2x]
=2.5+0.5*√2sin(2x-45) (x∈R)sin(2x-45) [-1,1]
值域
[5/2-√2/2,5/2+√2/2]