We apply the arguments from elementary calculus that are used to differentiate cosine and sine to hyperbolic cosine and hyperbolic sine, and by so doing produce the natural exponential function by ...

A PHASE relation familiar to students of applied mathematics exists between a simple harmonic oscillation and its derivative. Similar relations exist between exponential functions and their ...

This paper introduces a notion of 2-orthogonality for a sequence of polynomials to give extended versions of the Meixner and Feinsilver characterization results based on orthogonal polynomials. These ...