Answer to Question #288909 in Microeconomics for Hafsa Abdillahi

Question

Write down the matrix of the quadratic form

Q(x1,x2,x3,x4) = x12 +2x2 −7x32 +x42 −4x1x2 +8x1x3 −6x3x4

Answer 1

$A=\begin{pmatrix} 1 &-2 &4&0 \\ -2&2&0&0\\ 4&0&-7&-3\\ 0 &0&-3& 1 \end{pmatrix}$