Finding the solution of the wave equation that satisfies the boundary conditions

Jack_O
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Homework Statement



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Homework Equations



N/A

The Attempt at a Solution




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Really stuck with this, i can't work out how to apply the boundary conditions to generate the simultaneous equations to find the specific solution. Can't find any similar examples either.
Help appreciated.
 
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Do you know D'Alambert's formula? It will give you the solution almost immediately!
 
Just looked it up on wikipedia but it confuses me, it doesn't explain it very well.
 
You need to translate their notation to yours. They put it thusly.

u_{tt}-c^2u_{xx}=0

The subscripts indicate partial differentiation, ie u_{tt}=\frac{\partial^2u}{\partial t^2}. So their g(x) equals your e^{-x^2} and their h(x) equals your 2cxe^{-x^2}. It's just plug and chug from there.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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