We now assume $\lambda \neq 0$. Give a necessary and sufficient condition for the differential equation (II.2) $$z''(\theta) + \lambda z(\theta) = 0$$ to admit non-zero $2\pi$-periodic solutions. Give these solutions.
We now assume $\lambda \neq 0$. Give a necessary and sufficient condition for the differential equation (II.2)
$$z''(\theta) + \lambda z(\theta) = 0$$
to admit non-zero $2\pi$-periodic solutions. Give these solutions.