At $t=0$ the particle of Problem $5.1$ has the wavefunction
$$
\psi(x)= \begin{cases}1 / \sqrt{2 a} & \text { for }|x|<a \\ 0 & \text { otherwise }\end{cases}
$$
Find the probabilities that a measurement of its energy will yield: (a) $9 \hbar^{2} \pi^{2} /\left(8 m a^{2}\right) ;$ (b) $16 \hbar^{2} \pi^{2} /\left(8 m a^{2}\right)$