Verifying a solution to DE. totally stuck

  • Thread starter Thread starter darryw
  • Start date Start date
  • Tags Tags
    Stuck
Click For Summary
SUMMARY

The discussion focuses on verifying that \( y_1(t) = t \) is a solution to the differential equation \( t^2y'' - t(t+2)y' + (t+2)y = 0 \). The method of reduction of order is recommended to find a second linearly independent solution. The participant initially struggles with the presence of variable coefficients and the concept of characteristic polynomials, which are not applicable in this context. Ultimately, the solution involves substituting \( y_2(t) = u(t)y_1(t) = tu(t) \) into the differential equation to derive \( u(t) \).

PREREQUISITES
  • Understanding of second-order differential equations
  • Familiarity with the method of reduction of order
  • Knowledge of variable coefficient differential equations
  • Basic skills in substituting functions into differential equations
NEXT STEPS
  • Study the method of reduction of order in differential equations
  • Learn about variable coefficient differential equations
  • Practice verifying solutions to differential equations with variable coefficients
  • Explore resources on solving second-order linear differential equations
USEFUL FOR

Students studying differential equations, particularly those struggling with variable coefficients and the method of reduction of order. This discussion is beneficial for anyone looking to deepen their understanding of second-order linear differential equations.

darryw
Messages
124
Reaction score
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
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:
 
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
 

Similar threads

Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
2
Views
1K
  • · Replies 2 ·
Replies
2
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
4
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K