lim (x³-sinx)/x (0/0)
x->0
=lim (3x²-cosx)
x->0
=-1
x—>0,x³-sinx为x的同阶无穷小0无穷)（a^n+b^n）^1/n=??（a^n+b^n）^1/n=？？？ 哪个1属于哪块？（a^n+b^n）^（1/n）lim(a^n+b^n)^1/n(n->0)=lim[a(1+(b/a)^n)^1/n] (n->0)=ae