已知多项式2X^3-X²+M有一个因式X-1,求常数M值.
问题描述:
已知多项式2X^3-X²+M有一个因式X-1,求常数M值.
答
2x3-x2+ x3 = x3- x2+ x3+M
= x2(x-1)+ x3+(M1/3)3
= x2(x-1) +(x+M1/3)(x2-x•M1/3+ M2/3)
要从中提出因子(x-1),则(x+M1/3)=(x-1)
则M1/3=-1 则M=-1