The Pendulum Swings Back

Abstract

In the previous chapter, we returned to the equation of the forced pendulum

$$ y'' + a \sin y = e, $$

assuming now that the forcing term e: R → R is a continuous T-periodic function, but not necessarily an odd function as it was in Chapter 5. It will be convenient to remember that $a = \tfrac{g} {\ell }$ where g is the gravitational constant and l is the length of the pendulum, and therefore a > 0.