limx趋向于无穷,x²-1/x²-5x+4求极限

limx趋向于无穷,x²-1/x²-5x+4求极限
limx趋向于无穷,x²-1/x²-5x+4求极限

limx趋向于无穷,x²-1/x²-5x+4求极限

lim（x²-1/x²-5x+4）
=lim(x-1)(x+1) / [(x-1)(x-4)]
=lim(x+1)/(x-4)
=lim（x-4+5）/(x-4)
=lim1+5/(x-4)
=1
lim下面有无穷符号