Sturm–Liouville theory
In mathematics and its applications, a Sturm–Liouville problem is a second-order linear ordinary differential equation of the form
d
d
x
[
p
(
x
)
d
y
d
x
]
+
q
(
x
)
y
=
−
λ
w
(
x
)
y
{\displaystyle {\frac {\mathrm {d} }{\mathrm {d} x}}\left[p(x){\frac {\mathrm {d} y}{\mathrm {d} x}}\right]+q(x)y=-\lambda w(x)y}
for given functions
p
(
x
)
{\displaystyle p(x)}
,
q
(
x
)
{\displaystyle q(x)}
and
w
(
x
)
{\displaystyle w(x)}
, together with some boundary conditions at extreme values of
x
{\displaystyle x}
. The goals of a given Sturm–Liouville problem are:
https://en.wikipedia.org/wiki/Sturm–Liouville_theory