On a General Method of Solving Second-Order Ordinary Differential Equations by Phase-Plane Displacements

The phase-plane-delta method of solving second-order differential equations has been illustrated by numerous examples involving graphical constructions. Test cases show good accuracy for practicable size of steps, but, in general, the degree of approximation can be inferred empirically only. The delta method is extremely simple to apply, even to complicated equations. A subprofessional assistant can be instructed quickly in how to use the method, and ordinarily will develop enough speed to become useful in a short time.