elliptic cylindrical coordinates sentence in Hindi

Examples

1. The three-dimensional wave equation, when expressed in elliptic cylindrical coordinates, may be solved by separation of variables, leading to the Mathieu differential equations.
2. An elegant action-angle variables solution for the Kepler problem can be obtained by eliminating the redundant four-dimensional coordinates \ boldsymbol \ eta in favor of elliptic cylindrical coordinates ( ?, ?, ?)