求方程2x3-3x2+1=0的解 具体地写出每步,
问题描述:
求方程2x3-3x2+1=0的解 具体地写出每步,
答
方程变形得:
2x³-2x²-x²+1
=2x²﹙x-1﹚-﹙x+1﹚﹙x-1﹚
=﹙x-1﹚﹙2x²-x-1﹚
=﹙x-1﹚﹙2x²-2x+x-1﹚
=﹙x-1﹚[2x﹙x-1﹚+﹙x-1﹚]
=﹙x-1﹚²﹙2x+1﹚=0,
∴x=1或x=-½