Quadrics Definition. Let $q$ be a quadratic form on $\mathbb{R}^n$ or $\mathbb{C}^n$. Then the corresponding quadric is $Q = \{[v] \in \RP^n \mid q(v) =0\}$ A conic is a quadric in $\RP^2$. How many indefinite non-degenerate quadratic forms exists in … Continue reading Lecture 16