方程x^3-6x^2-x+6=0所有根的积是?
问题描述:
方程x^3-6x^2-x+6=0所有根的积是?
A3 B-3 C4 D-6 E以上都不对
答
选D
x^3-6x^2-x+6=0
x^2(x-6) -(x-6) =0
(x-6)(x^2-1) =0
(x-6((x-1)(x+1) =0
x1 =6,x2 =1,x3 = -1
所以,三个根的积是:
x1*x2*x3 = -6.