Integrate problem
- To: mathgroup at smc.vnet.net
- Subject: [mg65493] Integrate problem
- From: "axman" <yuerlong at gmail.com>
- Date: Wed, 5 Apr 2006 06:55:37 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, Group
I am new to Mathematica and now meet one problem I can't solve by
self. First I defined 3 functions: h, f and g
\!\(\(h[t_] := \(-20\)*Cos[t] Exp[\(-t\)\/20];\)\[IndentingNewLine]
\(f[x_, y_] := Cos[x] Sin[y];\)\[IndentingNewLine]
\(g[α_, β_, t_] :=
If[t == 0, \(-1\), If[h[t] <
β, \(-1\), If[h[t] > α, \(+1\), g[α, β, t - 0.1]]]];\)\)
Now I try to integrate the function f[x,y]*g[x,y,10] on a triangle
region:
\!\(â?«\_\(-20\)\%20\(â?«\_\(-20\)\%x\((N[f[
x, y]\ g[x, y, 10]])\) \[DifferentialD]y \[DifferentialD]x\)\)
The output result is strange. How to get correct answer for this
integration?
Thank you for help.