For the boundary value problem,
$y''+\lambda y=0$
$y(-π)=y(π)$ , $y’(-π)=y’(π)$
to each eigenvalue $\lambda$, there corresponds
- Only one eigenfunction
- Two eigenfunctions
- Two linearly independent eigenfunctions
- Two orthogonal eigenfunctions
I have tried to solve the problem but could not get my calculations right. Can somebody help?