For the third order differential equation, y′′′ = f(x, y, y′, y′′), we consider uniqueness implies existence results for solutions satisfying the nonlocal 4-point boundary conditions, y(x1) = y1, y(x2) = y2, y(x3)− y(x4) = y3. Uniqueness of solutions of such boundary value problems is intimately related to solutions of the third order equation satisfying certain nonlocal 3-point boundary condit...

In this article, we establish new Lyapunov-type inequalities for third-order linear differential equations y′′′ + q(t)y = 0 under the three-point boundary conditions y(a) = y(b) = y(c) = 0 and y(a) = y′′(d) = y(b) = 0 by bounding Green’s functions G(t, s) corresponding to appropriate boundary conditions. Thus, we obtain the best constants of Lyapunov-type inequalities for three-point boundary v...