Second Order Differential Equations
What is a second order differential equation?
- A second order differential equation is an equation containing second order derivatives (and possibly first order derivatives) but no higher order derivatives
- For example is a second order differential equation
- And so is
- But is not, because it contains the third order derivative
What are the types of second order differential equation?
- We divide second order differential equations into two main types
- A homogeneous second order differential equation is of the form where a, b and c are real constants
- You may also see this written in the form where and
- A non-homogeneous second order differential equation is of the form where a, b and c are real constants and where f(x) is a non-zero function of x
- You may also see this written in the form
How can I solve simple second order differential equations?
- If a second order differential equation is of the form , it will often be possible to solve it simply by using repeated integration
- A separate integration constant will need to be included for each of the integrations
- This means you will end up with two integration constants in your final answer
- To find the values of these constants you will need two separate initial or boundary conditions
- See the worked example below for examples of this