# The Grey Labyrinth is a collection of puzzles, riddles, mind games, paradoxes and other intellectually challenging diversions. Related topics: puzzle games, logic puzzles, lateral thinking puzzles, philosophy, mind benders, brain teasers, word problems, conundrums, 3d puzzles, spatial reasoning, intelligence tests, mathematical diversions, paradoxes, physics problems, reasoning, math, science.

Message body

 Emoticons View more Emoticons
 [quote="CzarJ"]Normally my Partial Differential Equations class is pretty easy, but I can't seem to get my head around this problem. I'm supposed to use Fourier transforms, convolutions, Gauss's kernel, and/or the error function to solve the heat equation: u[sub]t[/sub] = u[sub]xx[/sub], u(x,0) = 70*e[sup]-(x^2)/2[/sup]. All I've managed to do is use two different methods to get two different integrals I can't integrate. Any thoughts?[/quote]
Options
HTML is OFF
BBCode is ON
Smilies are ON
 Disable BBCode in this post Disable Smilies in this post

 All times are GMT
 Jump to: Select a forum Puzzles and Games----------------Grey Labyrinth PuzzlesVisitor Submitted PuzzlesVisitor GamesMafia Games Miscellaneous----------------Off-TopicVisitor Submitted NewsScience, Art, and CulturePoll Tournaments Administration----------------Grey Labyrinth NewsFeature Requests / Site Problems
 Topic review
Author Message
CzarJ
Posted: Sat Dec 09, 2006 2:52 am    Post subject: 1

I actually ended up figuring this one out--my stubbornness wouldn't allow me to seek any further help--but Bicho was right, for what it's worth. After a really weird-looking completion of the square and u-substitution, I ended up with the Gaussian. Go figure.
CzarJ
Posted: Sun Dec 03, 2006 7:12 am    Post subject: 0

Good idea--I will, when it's not 1 in the morning and me in my pajamas.
Bicho the Inhaler
Posted: Sun Dec 03, 2006 6:04 am    Post subject: -1

Why don't you post the integral? Chances are, it's the integral of a Gaussian in some form or other.
Lepton*
Posted: Fri Dec 01, 2006 2:17 pm    Post subject: -2

I have nothing, dude, sorry.
CzarJ
Posted: Wed Nov 29, 2006 8:30 pm    Post subject: -3

Normally my Partial Differential Equations class is pretty easy, but I can't seem to get my head around this problem.

I'm supposed to use Fourier transforms, convolutions, Gauss's kernel, and/or the error function to solve the heat equation:

u t = u xx , u(x,0) = 70*e -(x^2)/2 .

All I've managed to do is use two different methods to get two different integrals I can't integrate. Any thoughts?