I'm doing an undergrad research job..
I have encountered the following coupled 2nd order linear ODE with constant coefficients a, b, c, d...
\begin{align} \frac{d^2 y_1}{d x^2} + a^2y_1 & = -c y_2 \\
\frac{d^2 y_2}{d x^2} - b^2y_2 & = -d y_1 \end{align}
In addition, I...