A block is connected to two fixed walls by two springs. The equation of motion is
is the mass of the block,
is the displacement of the mass,
is time, and
are spring stiffness coefficients independent of
This example comes from , section 4.1, "Modeling with First Order Equations".
 J. R. Brannan and W. E. Boyce, Differential Equations with Boundary Value Problems: An Introduction to Modern Methods and Applications
, New York: John Wiley and Sons, 2010.
(United States Military Academy West Point, Department of Mathematics)