求值域(2)y=sinxcosx+sinx+cosx

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求值域(2)y=sinxcosx+sinx+cosx
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求值域(2)y=sinxcosx+sinx+cosx
求值域(2)y=sinxcosx+sinx+cosx

求值域(2)y=sinxcosx+sinx+cosx
令a=sinx+zosx
=√2(√2/2*sinx+√2/2zosx)
=√2(sinxzosπ/4+zosxsinπ/4)
=√2sin(x+π/4)
所以-√2

y=sinxcosx+sinx+cosx
=1/2*sin2x+2sin(x+π/4)
=-1/2*cos(2x+π/2)+√2sin(x+π/4)
=-1/2+[sin(x+π/4)]^2+√2sin(x+π/4)
=[sin(x+π/4)+√2/2]^2-1
-1+√2/2=0=<[sin(x+pi/4)+√2/2]^2=<3/2+√2
-1=