Partial Differentials and wave equation.

In summary, to determine if a function is a solution of a wave equation, one can differentiate the function twice with respect to 'x' and 't' and equate it to the product of 1/c² and the second derivatives. For the given functions, plugging them into the wave equation results in 1=1 or 0=0, indicating that they satisfy or do not satisfy the wave equation.
  • #1
hhhmortal
176
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
  • #2
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:
  • #3
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!
 

Question 1: What is a partial differential equation?

A partial differential equation is a mathematical equation that involves multiple variables and their partial derivatives. It is used to describe the relationship between these variables and how they change with respect to each other.

Question 2: How is the wave equation related to partial differential equations?

The wave equation is a type of partial differential equation that describes how waves propagate through a medium. It is commonly used in physics and engineering to study the behavior of waves.

Question 3: What is the difference between a partial differential equation and an ordinary differential equation?

A partial differential equation involves multiple independent variables and their partial derivatives, while an ordinary differential equation only involves one independent variable and its derivatives. Additionally, the solutions to partial differential equations are functions of multiple variables, while the solutions to ordinary differential equations are functions of a single variable.

Question 4: What are some applications of partial differential equations in real-world problems?

Partial differential equations are used in various fields such as physics, engineering, economics, and biology to model and solve problems involving changing systems. Some common applications include heat transfer, fluid dynamics, and electrostatics.

Question 5: How do you solve a partial differential equation?

The methods for solving a partial differential equation depend on the specific equation and its boundary conditions. Some common techniques include separation of variables, Fourier series, and numerical methods such as finite differences or finite elements. It is important to choose the appropriate method based on the problem at hand and the desired level of accuracy.

Similar threads

  • Calculus and Beyond Homework Help
Replies
7
Views
282
  • Calculus and Beyond Homework Help
Replies
10
Views
912
  • Calculus and Beyond Homework Help
Replies
0
Views
163
  • Calculus and Beyond Homework Help
Replies
5
Views
988
  • Calculus and Beyond Homework Help
Replies
1
Views
279
Replies
4
Views
499
  • Calculus and Beyond Homework Help
Replies
5
Views
912
  • Calculus and Beyond Homework Help
Replies
1
Views
442
  • Calculus and Beyond Homework Help
Replies
6
Views
2K
  • Calculus and Beyond Homework Help
Replies
18
Views
1K
Back
Top