- 46

- 0

[tex]

\frac {d^2} {d \phi^2} f(\phi) = q f(\phi)

[/tex]

I need to solve for f, and the solution indicates the answer is:

[tex]

f_{\substack{+\\-}} (\phi) = A e^{\substack{+\\-} \sqrt{q} \phi}

[/tex]

I know I've covered this before - just need a refresher on how to solve.