The Daily Trap
One Part C question, the same one for everyone, every morning. Four statements, four true-or-false calls — and like the real paper, only the exact correct set scores. No account, no sign-up.
Daily Trap · No. 2
Inner Product Spaces and Forms › Quadratic forms, positive definiteness, Sylvester's law
Let Q(x, y, z) = 2x² + 2y² + 2z² + 2xy + 2yz + 2zx. Which of the following are true?
The matrix of Q has eigenvalues 4, 1, 1.
All four count. Part C scores only for the exact correct set.