How Do You Determine p(x) and q(x) in a Second Order ODE with Given Solutions?

  • Thread starter Thread starter brad sue
  • Start date Start date
Click For Summary
SUMMARY

The discussion focuses on determining the coefficients p(x) and q(x) in a second-order ordinary differential equation (ODE) given the fundamental solutions x^2 + 2 and x^2 - 2. The correct approach involves substituting these solutions into the standard form of the ODE, y'' + p(x)y' + q(x)y = 0, and recognizing that the derivatives of both solutions are identical. The conclusion is that p(x) and q(x) cannot both be zero; instead, they must be solved as variables with respect to a constant x.

PREREQUISITES
  • Understanding of second-order ordinary differential equations (ODEs)
  • Familiarity with fundamental solutions and their derivatives
  • Knowledge of variable separation in differential equations
  • Basic algebraic manipulation skills
NEXT STEPS
  • Study the method of undetermined coefficients in ODEs
  • Learn about the Wronskian and its application in determining linear independence of solutions
  • Explore the theory behind linear differential equations and their solutions
  • Investigate the role of constant coefficients in second-order ODEs
USEFUL FOR

Students and professionals in mathematics, particularly those studying differential equations, as well as educators seeking to deepen their understanding of ODE solutions and their properties.

brad sue
Messages
270
Reaction score
0
Hi ,
please can I have your help?

x^2+2 and x^2-2 are fundamental set of solutions of a second order ODE. find the ODE.
form:y''+p(x) y'+ q(x) y=0.


I tried to replace the two solutions in the equation but because those solutions have exact same first and second derivatives, I found p(x)=q(x)=0 !

Can you help me to find p(x) and q(x)?
Thank you
B.
 
Physics news on Phys.org
Try again. Write out the two equations you get and solve for p and q as if they were variables and x was a constant. The two equations will be identical except for the factor in front of q (ie, y), since the two solutions only differ in their constant term (so that all their derivatives will be equal).
 

Similar threads

Replies
4
Views
2K
  • · Replies 18 ·
Replies
18
Views
4K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
Replies
2
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K