f(x1,x2,x3)=x1^2-2x2^2-2x3^2-4x1x2+4x1x3+8x2x3化为标准型.并写出所做的非退化线性变换
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f = (x1-2x2+2x3)^2-6x2^2-6x3^2+16x2x3= (x1-2x2+2x3)^2-6(x2-4/3x3)^2+(14/3)x3^2令 (y1,y2,y3)' = (x1-2x2+2x3,x2-4/3x3,x3)',线性变换矩阵为1 -2 20 1 -4/30 0 1则标准形为 f = y1^2-6y2^2+(14/3)y3^2....