Wave equation, separation of variables and the Laplace transform

[Johny911]

Homework Statement

Homework Equations

If i solve the wave equation using separation of variable and laplace tranform. Will i get the same answer ?

The Attempt at a Solution

 

[Ray Vickson]

Homework Statement

Homework Equations

If i solve the wave equation using separation of variable and laplace tranform. Will i get the same answer ?

The Attempt at a Solution

Take an example. Try both methods. What do you get?

 

[Johny911]

sometimes they are equal but sometimes they are not

 

[Ray Vickson]

sometimes they are equal but sometimes they are not

OK, so there's your answer.

But that just gets you started: why can they ever be unequal? What kind of problem gives you that? And: are you sure you have not made an error?

Maybe more details would be helpful.