  This study considers the stability of a non-inflectional elastica under a
conservative end force subject to the Dirichlet, mixed, and Neumann boundary
conditions. It is demonstrated that the non-inflectional elastica subject to
the Dirichlet boundary conditions is unconditionally stable, while for the
other two boundary conditions, sufficient criteria for stability depend on the
signs of the second derivatives of the tangent angle at the endpoints.
