Question

高数求极限（题目见图），要过程？

挺急的，在线等 T﹏T

Answer 1

f(x)=x^3-x^2-x+1
f(-1)=0
x^3-x^2-x+1=(x+1)(x^2+ax+1)
coef. of x
1+a =-1
a=-2
x^3-x^2-x+1
=(x+1)(x^2-2x+1)
=(x+1)(x-1)^2
g(1) =2x^3-3x^2 +1 =0
2x^3-3x^2 +1 =(x-1)(2x^2+bx-1)
coef. of x
-1-b=0
b=-1
2x^3-3x^2 +1
=(x-1)(2x^2-x-1)
=(x-1)(2x+1)(x-1)
//
lim(x->1) (x^3-x^2-x+1)/(2x^3-3x^2 +1)
=lim(x->1) (x+1)(x-1)^2 /[(x-1)(2x+1)(x-1)]
=lim(x->1) (x+1) /(2x+1)
=2/3