5.2 p. 264 \#21 (a)
\begin{equation*}
y''- 2xy'+\lambda y = 0,\qquad -\infty < x < \infty,
\end{equation*}
where $\lambda$ is a constant, is known as the Hermite equation. It is an important equation in mathematical physics.
Find the first four terms in each of two solutions about $x = 0$ and show that they form a fundamental set of solutions.
