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author | luccul <luccul@gmail.com> | 2010-07-06 06:04:12 +0000 |
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committer | bnewbold <bnewbold@adelie.robocracy.org> | 2010-07-06 06:04:12 +0000 |
commit | af9714204bd568e6fd73ed35b349ea1ca472d9b5 (patch) | |
tree | 92efea2d97d73478a48d290a51bbb6016046b90b | |
parent | 802c90d926a3ffc36dec7b4c792a36419eb6f7aa (diff) | |
download | afterklein-wiki-af9714204bd568e6fd73ed35b349ea1ca472d9b5.tar.gz afterklein-wiki-af9714204bd568e6fd73ed35b349ea1ca472d9b5.zip |
more more formatting
-rw-r--r-- | ClassJuly5.page | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/ClassJuly5.page b/ClassJuly5.page index ff7cfb3..664c440 100644 --- a/ClassJuly5.page +++ b/ClassJuly5.page @@ -56,10 +56,10 @@ and to satisfy $b(L) = 0$, we must impose a constraint on $\lambda$: $$ \lambda = \frac{\pi n}{L} $$ So, the most general solution we can generate in this manner is: -$$ u(x,t) = \sum_{n = 1}^{\infty} c_n e^{-(\frac{\pi n}{L})^2t} \sin(\frac{\pi n x}{L}) $$ +$$ u(x,t) = \sum_{n = 1}^{\infty} c_n e^{-\frac{\pi^2 n^2 t}{L^2}} \sin \left(\frac{\pi n x}{L} \right) $$ We would like to assert that any solution takes this form. One way to prove this assertion would be to show that any function $f:[0,L] \to \mathbb{R}$ satisfying $f(0) = f(L) = 0$ has a unique ``[Fourier sine expansion](http://mathworld.wolfram.com/FourierSineSeries.html)'': -$$ f(x) = \sum_{n = 1}^{\infty} c_n \sin(\frac{\pi n x}{L}) $$ +$$ f(x) = \sum_{n = 1}^{\infty} c_n \sin\left(\frac{\pi n x}{L}\right) $$ One could then allow the coefficients $c_n$ to vary with $t$ and apply the same method of solution that we used in the case of periodic boundary conditions. |