2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/71631We develop techniques for computing the AK invariant of a domain with arbitrary characteristic. We use these techniques to describe for any field $K$ the automorphism group of $K[X,Y,Z]/(X^n Y - Z^2 - h(X)Z)$, where $h(0) \ne 0$ and $n \geq 2$, as well as the isomorphism classes of these algebras.Commutative AlgebraAlgebraic Geometry14J50; 13A50, 14R10text