2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/165729We calculate the hyperelliptic Hodge integral lambda_g lambda_{g-1} / (1 - psi) for use in arXiv:math/0702219. The proof uses the WDVV equations for the genus zero Gromov--Witten invariants of P(1,1,2).5 pages; any comments welcomeAlgebraic Geometry14N35text