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问题: 极限

求(X^3-3X+2)/(X^4-4X+3),X→1的极限

解答:

X→1
x^3-3x+2 = (x-1)(x²+x-2) = (x-1)²(x+2)
x^4-4x+3 = (x-1)(x³+x²+x-3)=(x-1)²(x²+2x+3)

lim[(x^3-3x+2)/(x^4-4x+3)]
=lim[(x+2)/(x²+2x+3)]
=(1+2)/(1+2+3)
=1/2