Error in ODE-Solver-Documentation

[T-KS]

On page https://docs.sympy.org/latest/modules/solvers/ode.html
should'nt the description of 2nd_power_series_ordinary be
P(x)*y''(x) + Q(x)*y'(x) + R(x)*y(x)=0
and 2nd_power_series_regular same
P(x)*y''(x) + Q(x)*y'(x) + R(x)*y(x)=0
instead of P(x)*y''(x) + Q(x)*y'(x) + R(x)=0 both?

[ThePauliPrinciple]

Yes, I also understand a second order homogeneous differential equation to have y(x) in the last term. (for convenience https://docs.sympy.org/latest/modules/solvers/ode.html#nd-power-series-regular)

[oscarbenjamin]

This is probably just a typo

[T-KS]

Yes, I also think it's a typo, but I didn't find a place to correct it (or an email ...)

[ThePauliPrinciple]

A PR needs to be made which fixes the typos here

sympy/sympy/solvers/ode/ode.py

Lines 2279 to 2291 in ed0bfd1

	def ode_2nd_power_series_ordinary(eq, func, order, match):
	r"""
	Gives a power series solution to a second order homogeneous differential
	equation with polynomial coefficients at an ordinary point. A homogeneous
	differential equation is of the form
	.. math :: P(x)\frac{d^2y}{dx^2} + Q(x)\frac{dy}{dx} + R(x) = 0
	For simplicity it is assumed that `P(x)`, `Q(x)` and `R(x)` are polynomials,
	it is sufficient that `\frac{Q(x)}{P(x)}` and `\frac{R(x)}{P(x)}` exists at
	`x_{0}`. A recurrence relation is obtained by substituting `y` as `\sum_{n=0}^\infty a_{n}x^{n}`,
	in the differential equation, and equating the nth term. Using this relation
	various terms can be generated.

and here

sympy/sympy/solvers/ode/ode.py

Lines 2424 to 2435 in ed0bfd1

	def ode_2nd_power_series_regular(eq, func, order, match):
	r"""
	Gives a power series solution to a second order homogeneous differential
	equation with polynomial coefficients at a regular point. A second order
	homogeneous differential equation is of the form
	.. math :: P(x)\frac{d^2y}{dx^2} + Q(x)\frac{dy}{dx} + R(x) = 0
	A point is said to regular singular at `x0` if `x - x0\frac{Q(x)}{P(x)}`
	and `(x - x0)^{2}\frac{R(x)}{P(x)}` are analytic at `x0`. For simplicity
	`P(x)`, `Q(x)` and `R(x)` are assumed to be polynomials. The algorithm for
	finding the power series solutions is:

[KuldeepBorkar]

Ok, I will fix the typo quickly.