lim(x/((1-x^2)^2)-x)x趋向于无穷
问题描述：
lim(x/((1-x^2)^2)-x)x趋向于无穷
答
lim(x->无穷)(x/ ((1-x^2)^2)-x)
=lim(x->无穷) x/ ( 1-x-2x^2+x^4 )
=lim(x->无穷) (1/x^4)/ ( 1/x^4 - 1/x^3- 2/x^2+ 1)
=0前面是一个分式 再减去x x不在分母里lim(x->无穷){ x/ ((1-x^2)^2)-x }=lim(x->无穷)[x-(x-2x^3+x^5)] /(1-2x^2+x^4)=lim(x->无穷)(2x^3-x^5) / (1-2x^2+x^4)=-无穷是不是分子最高次幂比分母要大而且x都趋向于无穷的答案都是无穷的？是