Finding the period of a differential equation?

Click For Summary
SUMMARY

The discussion focuses on finding the period of the solution to the differential equation 2y'' + 4y' + y = 0. The user correctly identifies the complementary equation 2r^2 + 4r + 1 = 0 and applies the quadratic formula, resulting in two distinct real roots. The conclusion drawn is that real, distinct roots indicate the absence of a periodic solution. The user inquires about the method for determining the period if the roots were complex, highlighting the periodic nature of e^(ix).

PREREQUISITES
  • Understanding of differential equations and their solutions
  • Familiarity with the quadratic formula and its application
  • Knowledge of complex numbers and their properties
  • Concept of periodic functions, particularly e^(ix)
NEXT STEPS
  • Study the characteristics of solutions to second-order linear differential equations
  • Learn about the implications of complex roots in differential equations
  • Explore the concept of periodicity in functions, specifically in relation to complex exponentials
  • Investigate the method of finding periods for oscillatory solutions in differential equations
USEFUL FOR

Mathematics students, educators, and professionals dealing with differential equations, particularly those interested in the analysis of periodic solutions.

adl2114
Messages
7
Reaction score
0
find the period of the solution to this differential equation:

2y'' + 4y' + y = 0

I used the complementary equation 2r^2 + 4r + 1 = 0 and then used the quadratic equation to factor that into 2 roots of -2 + 2^(1/2) and -2 - 2^(1/2) and I know that 2 real, distinct roots means there is no period but If the problem had been different how would I go about finding the period after determining the roots?
 
Physics news on Phys.org
Well, first, your roots are off by a scaling factor of 1/2. And assuming that both roots are imaginary, well, e^(ix) is periodic, but I'm not sure of the period...
 

Similar threads

  • · Replies 27 ·
Replies
27
Views
2K
Replies
6
Views
1K
Replies
5
Views
3K
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
Replies
4
Views
2K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K