Question

怎样求lim（x趋向1）时X的三次方-1 / X的平方-1的极限

Answer 1

因式分解

x^3-1=(x-1)(x^2+x+1)

x^2-1=(x-1)/(x+1)

limx趋向1x^2+X+1/x+1=3/2