x+y=π/3,则sinxsiny最大值

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x+y=π/3,则sinxsiny最大值
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x+y=π/3,则sinxsiny最大值
x+y=π/3,则sinxsiny最大值

x+y=π/3,则sinxsiny最大值
x+y=π/3 y=π/3-x
sinxsiny=sinxsin(π/3-x)
=sinx(√3/2cosx-1/2sinx)
=√3/2sinx*cosx-1/2sin^2x
=√3/4sin2x-(1-cos2x)/4
=√3/4sin2x+1/4cos2x-1/4
=1/2sin(2x+π/6)-1/4
所以当sin(2x+π/6)=1 时 最大值=1/2-1/4=1/4

x+y=π/3 y=π/3-x
sinxsiny=sinxsin(π/3-x)
=sinx(√3/2cosx-1/2sinx)
=√3/2sinx*cosx-1/2sin^2x
=√3/4sin2x-(1-cos2x)/4
=√3/4sin2x+1/4cos2x-1/4
=1/2sin(2x+π/6)-1/4
所以当sin(2x+π/6)=1 时 最大值=1/2-1/4=1/4

原式=sinxsin(π/3-x)
=sinx(√3/2*cosx-1/2*sinx)
=√3/4*sin2x+1/4*cos2x-1/4
所以最大值=√(3/16+1/16)-1/4=1/4
说实话,我看是嫌麻烦,没做
你不用采纳我