Diff Eq: Variation of Parameters for 3rd-ODE's

In summary, the variation of parameters method is used to find a particular solution to a 3rd-order differential equation when the general solution is already known. It differs from other methods because it can be used for any 3rd-order differential equation, regardless of its form. It can also be used for higher-order differential equations, but becomes more complex as the order increases. The steps involved include finding the general solution to the homogeneous equation, calculating the Wronskian, using it to find the particular solution, and then adding it to the general solution. However, it may not work for all 3rd-order differential equations, especially those with complex or non-constant coefficients. In these cases, other methods may be more suitable.
  • #1
UziStuNNa
9
0

Homework Statement



http://img27.imageshack.us/img27/6083/variationofparametersfop.jpg
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
I don't see any attempt to do anything yourself.
 
  • #3
Well I'm not sure how to start it off.
 
  • #4
UziStuNNa said:
Well I'm not sure how to start it off.

Then you need to tell us what is confusing you.
 
  • #5
[tex]W_1(t)[/tex]= [tex]g(t)(y_2(t)y_3'(t)-y_3(t)y_2'(t))[/tex]
[tex]W_2(t)[/tex]=[tex]-g(t)(y_1y_3'-y_3y_1')[/tex]
[tex]W_3(t)[/tex]=[tex]g(t)(y_1y_2'-y_2y_1')[/tex]

Then, [tex]u_1(t)=\int(W_1/W)[/tex] and so forth for [tex]u_2[\tex] and [tex]u_3[/tex]
 

1. What is the variation of parameters method used for in solving 3rd-order differential equations?

The variation of parameters method is used to find a particular solution to a 3rd-order differential equation when the general solution is already known. It allows us to find a solution that satisfies specific initial conditions.

2. How does the variation of parameters method differ from other methods of solving differential equations?

The variation of parameters method differs from other methods, such as separation of variables or the method of undetermined coefficients, because it does not require the equation to be in a specific form. It can be used for any 3rd-order differential equation, regardless of its form.

3. Can the variation of parameters method be used for higher-order differential equations?

Yes, the variation of parameters method can be used for any order of differential equation. However, it becomes more complex and time-consuming as the order increases.

4. What are the steps involved in using the variation of parameters method?

The steps involved in using the variation of parameters method are: 1) Find the general solution to the homogeneous equation; 2) Find the Wronskian of the homogeneous equation; 3) Use the Wronskian to find the particular solution; 4) Substitute the particular solution into the original equation and solve for the coefficients; 5) Add the particular solution to the general solution to get the final solution.

5. Are there any limitations to using the variation of parameters method?

The variation of parameters method may not work for all 3rd-order differential equations, especially those with complex or non-constant coefficients. In these cases, other methods may be more suitable for finding a particular solution.

Similar threads

  • Calculus and Beyond Homework Help
Replies
7
Views
501
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
2
Views
865
  • Calculus and Beyond Homework Help
Replies
2
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
905
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
1K
  • Calculus and Beyond Homework Help
Replies
1
Views
1K
  • Calculus and Beyond Homework Help
Replies
3
Views
999
  • Calculus and Beyond Homework Help
Replies
3
Views
957
Back
Top