A Trigonometric Sum (W. Böhm)

Also solved by D. L. HETP,ICK (University of Arizona) and the proposer. Editorial note. The proposer finds an analytic solution ofthe system for the special case in which the parameters are related by ah + bk 2h 2. In this instance, the nonlinear second-order equation that is obtained by eliminating x, + a + h + by) 19 + bhy + ah bk)y ak O, has the integrating factor exp (2ht) and the problem can be reduced to solving a Riccati equation. [C.C.R.]