(x^2-x-6)/(-x^2-1)＜0因x^2≥0故-x^2≤0故-x^2-1≤-1（即分母为负数，只要分子为正数即可）x^2-x-6>0(x-3)(x+2)>0x<-2 或 x>3
解：-x^2≤0-x^2-1<0所以x^2-x-6>0(x-3)(x+2)>0x>3或x<-2
原式化为(x^2-2x-6)/(x^2+1)=(x-3)(x+2)/(x^2+1)>0解集为x<-2或x>3
