已知集合A={(X,Y)|Y=-X^2+mx-1},B={(x,y)|x+y=3,0
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![已知集合A={(X,Y)|Y=-X^2+mx-1},B={(x,y)|x+y=3,0](/uploads/image/z/13934472-24-2.jpg?t=%E5%B7%B2%E7%9F%A5%E9%9B%86%E5%90%88A%3D%7B%EF%BC%88X%2CY%EF%BC%89%7CY%3D-X%5E2%2Bmx-1%7D%2CB%3D%7B%28x%2Cy%29%7Cx%2By%3D3%2C0)
已知集合A={(X,Y)|Y=-X^2+mx-1},B={(x,y)|x+y=3,0
已知集合A={(X,Y)|Y=-X^2+mx-1},B={(x,y)|x+y=3,0
已知集合A={(X,Y)|Y=-X^2+mx-1},B={(x,y)|x+y=3,0
相当于线段:x+y=3,0=
依题意有,3-x=-x^2+mx-1,在0<=x<=3上有唯一实数解。由,3-x=-x^2+mx-1得x^2-(m+1)x+4=0
设f(x)=x^2-(m+1)x+4,所以有,f(0)*f(3)<=0,即4×[3^2-(m+1)×3+4]<=0,解得m>=10/3.