In linear algebra and projective geometry, Gerbaldi's theorem, proved by Gerbaldi (1882), states that one can find six pairwise apolar linearly independent nondegenerate ternary quadratic forms. These are permuted by the Valentiner group.
- Gerbaldi, Francesco (1882), "Sui gruppi di sei coniche in involuzione" (in Italian), Torino Atti XVII: 566–580
Original source: https://en.wikipedia.org/wiki/ Gerbaldi's theorem. Read more