2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/76398We show how lattice paths and the reflection principle can be used to give easy proofs of unimodality results. In particular, we give a "one-line" combinatorial proof of the unimodality of the binomial coefficients. Other examples include products of binomial coefficients, polynomials related to the Legendre polynomials, and a result connected to a conjecture of Simion.7 pages (plus cover and abstract)Combinatoricstext