Is There a General Solution to This Second-Order ODE?

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In summary, there is no general analytical solution to the differential equation \frac{d}{dt}\left[p(t)\frac{dx(t)}{dt}\right] + q(t)x(t) = 0 for x(t) with arbitrary functions p(t) and q(t). This type of equation is known as a Sturm-Liouville problem or equation. While it may be possible to solve the equation using power series or numerical methods, there is no closed form solution.
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Is there a general solution to

[tex] \frac{d}{dt}\left[p(t)\frac{dx(t)}{dt}\right] + q(t)x(t) = 0 [/tex]

for [itex] x(t) [/itex] when [itex] p(t) [/itex] and [itex] q(t) [/itex] are arbitrary functions? Better yet, does this question have a name, or some identifier, that I could look in to? It might appear more familiar written as

[tex] \left[p(t)x^\prime\right]^\prime + q(t)x = 0 [/tex]
 
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Undoubtedly0 said:
Is there a general solution to
[tex] \frac{d}{dt}\left[p(t)\frac{dx(t)}{dt}\right] + q(t)x(t) = 0 [/tex]
for [itex] x(t) [/itex] when [itex] p(t) [/itex] and [itex] q(t) [/itex] are arbitrary functions?

No, there is no genertal solution
.
 

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  • #3
Undoubtedly0 said:
Is there a general solution to

[tex] \frac{d}{dt}\left[p(t)\frac{dx(t)}{dt}\right] + q(t)x(t) = 0 [/tex]

for [itex] x(t) [/itex] when [itex] p(t) [/itex] and [itex] q(t) [/itex] are arbitrary functions? Better yet, does this question have a name, or some identifier, that I could look in to? It might appear more familiar written as

[tex] \left[p(t)x^\prime\right]^\prime + q(t)x = 0 [/tex]

Look up Sturm-Liouville problems or equations.
 
  • #4
I think that's just a ODE with non constant coeffecients, since expanding yields

P(t)x''+P'(t)x'+q(t)x=0

You may be able to solve this with power series if P and q fit them.
Non linear differential equations rarely have closed form solutions.
But that's okay, we have computers
 
  • #5
Of course, when I say "There is no general solution", I mean "No general analytical solution espressed on a closed form".
Obviously, in some particular cases, with some particular forms of functions p(t) and q(t), the solutions might be known on closed form, and/or be expressed as infinite series.
Even more generally the solutions can be accurately approached thanks to numerical methods.
 

FAQ: Is There a General Solution to This Second-Order ODE?

What is a second-order ODE?

A second-order ordinary differential equation (ODE) is a mathematical equation that involves a dependent variable, its derivatives, and independent variables. It is called "second-order" because it contains the second derivative of the dependent variable.

How do you identify a second-order ODE?

A second-order ODE can be identified by looking for the highest derivative of the dependent variable. If the highest derivative is the second derivative, then the equation is a second-order ODE.

What is the general form of a second-order ODE?

The general form of a second-order ODE is F(x, y, y', y'') = 0, where x is the independent variable, y is the dependent variable, y' is the first derivative of y, and y'' is the second derivative of y.

How do you solve a second-order ODE?

The solution of a second-order ODE involves finding a function that satisfies the equation. This can be done through various techniques, such as separation of variables, substitution, or using specific methods for different types of equations (e.g. homogeneous, linear, etc.).

What are some real-life applications of second-order ODEs?

Second-order ODEs are commonly used in physics and engineering to model different phenomena, such as motion, vibrations, and electrical circuits. They are also used in economics, biology, and other fields to describe various processes and relationships between variables.

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