2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/95046We generalize the group law of curves of degree three by chords and tangents to the Jacobi variety of a hyperelliptic curve. In the case of genus 2 we accomplish the construction by a cubic parabola. We derive explicit rational formulas for the addition on a dense set in the Jacobian.5 pagesAlgebraic Geometry14H40text