Partial Differentials and wave equation.

Click For Summary
SUMMARY

This discussion focuses on determining whether specific functions are solutions to the wave equation, defined as \( f_{xx} = \frac{1}{c^2} f_{tt} \). The functions analyzed include \( xt \), \( \log(xt) \), and \( x^2 + c^2t^2 \). The user confirmed that \( x^2 + c^2t^2 \) satisfies the wave equation, while \( xt \) and \( \log(xt) \) do not yield valid results upon differentiation. The key takeaway is to differentiate each function twice with respect to \( x \) and \( t \) and check if the equation holds true.

PREREQUISITES
  • Understanding of wave equations and their mathematical formulation
  • Knowledge of partial differentiation techniques
  • Familiarity with the concepts of second derivatives
  • Basic proficiency in calculus, specifically in solving differential equations
NEXT STEPS
  • Study the derivation and properties of the wave equation in detail
  • Learn about the method of characteristics for solving partial differential equations
  • Explore examples of functions that satisfy the wave equation
  • Investigate the implications of boundary conditions on wave equation solutions
USEFUL FOR

Students and educators in mathematics, particularly those focusing on differential equations, as well as researchers and professionals working with wave phenomena in physics and engineering.

hhhmortal
Messages
175
Reaction score
0

Homework Statement



How can I find out if a function is a solution of a wave equation such as:

(a) xt
(b) log(xt)
(c) x² + c²t²



The Attempt at a Solution



Is it simply differentiating the funtion with respect to 'x' twice and equating this to the product of 1/c² and differentiating the function twice with respect to 't'?

I tried doing it for part (c) and I got 1=1 which means its allowed I guess. As for part (a) I got 0=0 which i suppose it isn't?
 
Physics news on Phys.org
Yes, just plug each function into the wave equation and see if they satisfy it: for each function, f, find fxx and ftt and see if they satisfy [itex]f_{xx}= (1/c^2) f_{tt}[/itex]
 
Last edited by a moderator:
Ok, thanks, most of the time they seem to be 1=1 or 0=0 hence satisfying and not satisfying the wave equation i suppose..thanks again!
 

Similar threads

  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 12 ·
Replies
12
Views
2K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
1
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
Replies
4
Views
2K