  Stability analysis is performed for a linear differential equation with two
delays. Geometric arguments show that when the two delays are rationally
dependent, then the region of stability increases. When the ratio has the form
1/n, this study finds the asymptotic shape and size of the stability region.
For example, a delay ration of 1/3 asymptotically produces a stability region
44.3% larger than any nearby delay ratios, showing extreme sensitivity in the
delays. The study provides a systematic and geometric approach to finding the
eigenvalues on the boundary of stability for this delay differential equation.
A nonlinear model with two delays illustrates how our methods can be applied.
