1. The problem statement, all variables and given/known data Make a change of variable that transforms the quadratic form with no cross-product term: 9x1^2 - 8x1x2 = 3x2^2 2. Relevant equations A = PDP^-1 Q = y^TDy 3. The attempt at a solution I know the answer. This is a question regarding concept. The eigenvalues for this problem are 1 and 11. The order in which I construct D affect the coefficients of the quadratic form following a change of variable. Consider constructing D as either 1 0 0 11 or 11 0 0 1 The two resulting quadratic forms would have their coefficients switched. Basically, I'm asking, is this ok? Would both answers be acceptable?