f(x1,x2,x3)=2x1x2+2x1x3+2x2x3怎么用配方法化为标准型?

分类: 作业答案 • 2022-01-09 21:45:07

问题描述：

答

f(x1,x2,x3)=2x1x2+2x1x3+2x2x3
=2(y1+y2)(y1-y2)+2(y1+y2)y3+2(y1-y2)y3
=2y1^2 + 4y1y3 - 2y2^2
= 2(y1+y3)^2 - 2y2^2 - 2y3^2
= 2z1^2 - 2z2^2 -2z3^2