Khan Academy on a Stick
Second order linear equations
Linear differential equations that contain second derivatives
-
2nd Order Linear Homogeneous Differential Equations 1
cc
Introduction to 2nd order, linear, homogeneous differential equations with constant coefficients.
-
2nd Order Linear Homogeneous Differential Equations 2
cc
Let's find the general solution!
-
2nd Order Linear Homogeneous Differential Equations 3
cc
Let's use some initial conditions to solve for the particular solution
-
2nd Order Linear Homogeneous Differential Equations 4
cc
Another example with initial conditions!
Linear homogeneous equations
To make your life interesting, we'll now use the word "homogeneous" in a way that is not connected to the way we used the term when talking about first-order equations. As you'll see, second order linear homogeneous equations can be solved with a little bit of algebra (and a lot of love).
-
Complex roots of the characteristic equations 1
cc
What happens when the characteristic equations has complex roots?!
-
Complex roots of the characteristic equations 2
cc
What happens when the characteristic equation has complex roots?
-
Complex roots of the characteristic equations 3
cc
Lets do an example with initial conditions!
-
Repeated roots of the characteristic equation
cc
What happens when the characteristic equation only has 1 repeated root?
-
Repeated roots of the characteristic equations part 2
cc
An example where we use initial conditions to solve a repeated-roots differential equation.
Complex and repeated roots of characteristic equation
Thinking about what happens when you have complex or repeated roots for your characteristic equation.
-
Undetermined Coefficients 1
cc
Using the method of undetermined coefficients to solve nonhomogeneous linear differential equations.
-
Undetermined Coefficients 2
cc
Another example using undetermined coefficients.
-
Undetermined Coefficients 3
cc
Another example where the nonhomogeneous part is a polynomial
-
Undetermined Coefficients 4
cc
Putting it all together!
Method of undetermined coefficients
Now we can apply some of our second order linear differential equations skills to nonhomogeneous equations. Yay!