Given a positive integer n and an exponent 1 ≤ α ≤ ∞. We will find explicitly the optimal bound rn such that if the L α norm of a potential q(t) satisfies q L α (I) < rn then the n th Dirichlet eigenvalue of the onedimensional p-Laplacian with the potential q(t):`|u | p−2 u ´ + (λ + q(t)) |u| p−2 u = 0 (1 < p < ∞) will be positive. Using these bounds, we will construct, for the Dirichlet, the Neumann, the periodic or the antiperiodic boundary conditions, certain classes of potentials q(t) so that the p-Laplacian with the potential q(t) is non-degenerate, which means that the above equation with λ = 0 has only the trivial solution verifying the corresponding boundary condition.