f(x1,x2,x3)=x1^2+2x1x2+x2^2+2x2x3+x3^2+2x3x4+x4^2用配方法化下列二...
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发布时间：2024-10-24 09:33
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热心网友
时间：2024-11-18 18:16
f = (x1+x2)^2+x3^2+x4^2+2x2x3+2x3x4
= (x1+x2)^2+(x3+x4)^2+2x2x3
= y1^2+y2^2+2y3^2-2y4^2
y1=x1+x2
y2=x3+x4
x2=y3-y4
x3=y3+y4
即
x1=y1-y3+y4
x2=y3-y4
x3=y3+y4
x4=y2-y3-y4
