# 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.

Author Message
CzarJ
Hot babe

 Posted: Wed Nov 29, 2006 8:30 pm    Post subject: 1 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?
Lepton*
Guest

 Posted: Fri Dec 01, 2006 2:17 pm    Post subject: 2 I have nothing, dude, sorry.
Bicho the Inhaler
Daedalian Member

 Posted: Sun Dec 03, 2006 6:04 am    Post subject: 3 Why don't you post the integral? Chances are, it's the integral of a Gaussian in some form or other.
CzarJ
Hot babe

 Posted: Sun Dec 03, 2006 7:12 am    Post subject: 4 Good idea--I will, when it's not 1 in the morning and me in my pajamas.
CzarJ
Hot babe

 Posted: Sat Dec 09, 2006 2:52 am    Post subject: 5 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.
 Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year by All usersAnonymousBicho the InhalerCzarJ Oldest FirstNewest First
 All times are GMT Page 1 of 1

 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
You cannot post new topics in this forum
You can reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum