ax^2-(a+3)+3<0(a∈R)ax^2-a<0a(x^2-1)<0a=0 x无解a<0 (x^2-1)>0 x^2>1 x>1 x<-1a>0 x^2-1<0 -1ax^2-(a+3) x +3<0ax^2-ax-3x+3<0ax(x-1)-3(x-1)<0(ax-3)(x-1)<0ax-3>0 x-1<0 x>3/a x<1 a[0,3)时x无解 a>3时3/aax-3<0 x-1>0 x<3/a x>1 a<0,a>=3时x无解, a(0,3)时 1a=0时ax^2-(a+3) x +3<0变成-3x+3<0 x>1a>3时3/aa<0时 3/aa(0,3)时 1a=0时x>1