Fourier series and elliptic functions.

Non-linear second-order differential equations whose solutions are the elliptic functions sn ( t, k ), cn ( t, k ) and dn ( t, k ) are investigated. Using Mathematica , high precision numerical solutions are generated. From these data, Fourier coefficients are determined yielding approximate formulas for these non-elementary functions that are correct to at least 11 decimal places. These formulas have the advantage over numerically generated data that they are computationally efficient over the entire real line. This approach is seen as further justification for the early introduction of Fourier series in the undergraduate curriculum, for by doing so, models previously considered hard or advanced, whose solution involves elliptic functions, can be solved and plotted as easily as those models whose solutions involve merely trigonometric or other elementary functions. [ABSTRACT FROM AUTHOR]