I need some help to locate and classify the singular points of
$$y′′+ 4y = 0$$
then make conclusion on existence of solutions in powers of $x,(x−1),(x+1)$.
so I know that $p(x)=0$ since there is no $y′$ and $q(x)=4$ so does that mean that $x = 0$ is an irregular singular point? Is that the only one?