fundamental discriminant
integer invariant of integral binary quadratic forms, associating the integer 𝑏²−4𝑎𝑐 to the quadratic form 𝑎𝑥²+𝑏𝑥𝑦+𝑐𝑦²
integer invariant of integral binary quadratic forms, associating the integer 𝑏²−4𝑎𝑐 to the quadratic form 𝑎𝑥²+𝑏𝑥𝑦+𝑐𝑦²