16.-Linear-Algebra-by-Kenneth-Hoffman · Problem 10.2.3
Bilinear Forms
Mathematics — Linear Algebra · non-degenerate-quadratic-form
Problem
Let q(x1,x2)=ax12+bx1x2+cx22 be the quadratic form associated with a symmetric bilinear form f on R2. Show that f is non-degenerate if and only if b2−4ac=0.