Question

1 2 3 矩阵A=【 0 1 -2 】对应的二次型是?0 0 -1

Answer 1

1 2 3

0 1 -2

0 0 -1

f(x1,x2,x3) = x1^2+x2^2-x3^2+2x1x2+3x1x3-2x2x3