2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114996Results obtained by Joseph ({\it J. Fluid Mech.} {\bf 33} (1968) 617) for the viscous parallel shear flow problem are extended to the problem of viscous parallel, shear flow problem in the beta plane and a sufficient condition for stability has also been derived.6 pagesMathematical PhysicsBounds on the phase velocity in the linear instability of viscous shear flow problem in the $β$-planetext