怎么求最小值 (x^3-6x+5)/(x-1)的最小值
问题描述:
怎么求最小值 (x^3-6x+5)/(x-1)的最小值
答
(x³-6x+5)/(x-1)
=[x³-x-(5x-5)]/(x-1)
=[x(x²-1)-5(x-1)]/(x-1)
=x(x+1)-5
=x²+x-5
=(x+1/2)²-21/4
最小值-21/4