2x^3+x^2+1=0的解法～求详解!好的加分···
问题描述：
2x^3+x^2+1=0的解法～
求详解!好的加分···
答
x^3+x^2+x^3+1=0
x^2(x+1)+(x+1)(x^2-x+1)=0
(x+1)(x^2+x^2-x+1)=0
(x+1)(2x^2-x+1)=0
2x^2-x+1=0无解
所以 x=-1
答
原方程：
2x^3+2x^2-x^2-x+x+1=0
2x^2(x+1)-x(x+1)+x+1=0
(x+1)(2x^2-x+1)=0
所以有x=-1
答
2x^3+x^2+1=0x^3+x^2+x^3+1=0x^2(x+1)+(x+1)(x^2-x+1)=0(x+1)(x^2+x^2-x+1)=0(x+1)(2x^2-x+1)=0(x+1)(x^2-x/2+1/2)=0(x+1)(x^2-x/2+1/16-1/16+1/2)=0(x+1)[(x-1/2)^2+7/16]=0[(x-1/2)^2+7/16]>0所以(x+1)=0x=-1