Verifying a solution to DE. totally stuck

  • Thread starter darryw
  • Start date
  • Tags
    Stuck
In summary, the conversation discusses verifying a given function as a solution to a differential equation, using reduction of order to find a second linearly independent solution, and difficulties with understanding the method and using it to solve the problem. The individual ultimately figures out the solution through independent research and expresses frustration with the complexity of the topic and the high cost of the required textbook.
  • #1
darryw
127
0

Homework Statement



verify that y_1(t) = t is solution of t^2y'' - t (t+2)y' + (t+2)y = 0

use "reduction of order to find 2nd linerary independent solution of equation

Homework Equations



I am stuck on the first part. Confused as to how (which method) I am expected to use to verify.
im stuck on getting the characteristic because of all the extra t's in the eqn.
im used to something with just y's like this: y'' + 5y' -7y = 0
but i don't know how to treat the t's

also when i try getting integrating factor, it doesn't work because its 2nd order (right?)
please help I am totally stuck thanks

The Attempt at a Solution

 
Physics news on Phys.org
  • #2
darryw said:
Confused as to how (which method) I am expected to use to verify.

Simple. Substitute [itex]y=t[/itex] into your differential equation...if you get 0=0 as a result, then it satisfies the DE.

im stuck on getting the characteristic because of all the extra t's in the eqn.

This isn't a constant coefficients problem, you aren't looking for the characteristic polynomial. You are supposed to use reduction of order instead.

Basically, once you verify that [itex]y_1(t)=t[/itex] is a solution, you look for a second, linearly independent solution, of the form [itex]y_2(t)=u(t)y_1(t)=tu(t)[/itex] by substituting this assumed form into your DE and solving the resulting DE you get for [itex]u(t)[/itex].

I'm sure your textbook covers this method, so if you have difficulties, try opening your textbook and reading the relevant section :wink:
 
  • #3
Thanks I figured this out. btw the textbook for this class is $197! its crazy. Professor always seem to make it so complicated too, so i just learn it all on youtube.
thanks for the help
 

1. How do I verify a solution to a differential equation?

To verify a solution to a differential equation, you must substitute the solution into the original equation and check if it satisfies the equation. This means that the derivative of the solution should equal the original equation. If it does, then the solution is verified.

2. What if the solution doesn't satisfy the differential equation?

If the solution does not satisfy the differential equation, then it is not a valid solution. This means that you may have made a mistake while solving the differential equation or your solution is incorrect. Double-check your work and try again.

3. Is it necessary to verify a solution to a differential equation?

Yes, it is important to verify a solution to a differential equation to ensure its accuracy and validity. This step helps to avoid any mistakes made during the solving process and to confirm that the solution is indeed a solution to the given differential equation.

4. Can I use any solution to a differential equation without verifying it?

No, you should always verify a solution to a differential equation before using it. Using an unverified solution may lead to incorrect results and can cause problems in further calculations or applications of the differential equation.

5. How do I know if my solution is the only solution to a differential equation?

To determine if a solution is unique, you can use the existence and uniqueness theorem for differential equations. This theorem states that if the function and its derivative are continuous on a given interval, then the solution to the differential equation is unique on that interval. You can also check if there are any initial conditions given, as this can also determine the uniqueness of a solution.

Similar threads

  • Calculus and Beyond Homework Help
Replies
7
Views
681
  • Calculus and Beyond Homework Help
Replies
5
Views
284
  • Calculus and Beyond Homework Help
Replies
2
Views
316
  • Calculus and Beyond Homework Help
Replies
2
Views
185
  • Calculus and Beyond Homework Help
Replies
3
Views
568
  • Calculus and Beyond Homework Help
Replies
1
Views
703
  • Calculus and Beyond Homework Help
Replies
0
Views
161
  • Calculus and Beyond Homework Help
Replies
5
Views
1K
  • Calculus and Beyond Homework Help
Replies
4
Views
936
  • Calculus and Beyond Homework Help
Replies
8
Views
229
Back
Top