2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73308Let ${\mathbb F}_q$ be a finite field of characteristic two and ${\mathbb F}_q(X_1,...,X_n)$ a rational function field. We use matrix methods to obtain explicit transcendental bases of the invariant subfields of orthogonal groups and pseudo-symplectic groups on ${\mathbb F}_q(X_1,...,X_n)$ over ${\mathbb F}_q$.20 pagesCommutative AlgebraGroup Theory20G40;13A50;16W22text