The integrand has evaluated to non-numerical values for all
- To: mathgroup at smc.vnet.net
- Subject: [mg83838] The integrand has evaluated to non-numerical values for all
- From: Kreig Hucson <kreig.hucson at yahoo.com>
- Date: Sun, 2 Dec 2007 04:06:28 -0500 (EST)
Hi all,
Being given the function:
f[x_,y_]:= Sin[x*y]*Exp[-(y-1)^2]/(x*y) ,
I want to integrate it with respect to y, from 0 to Infinity, and to obtain a function of x only, F[x].
I typed the command:
F[x_]:= Assuming[x>0, Integrate[f[x,y],{y,0,Infinity}]]
but the integral remained unevaluated by Mathematica 6.
After this, I typed the command:
F[x_]:= Assuming[x>0, NIntegrate[f[x,y],{y,0,Infinity}]]
but I received the error message: "The integrand f[x,y] has evaluated to non-numerical values for all sampling points in the region with boundaries {{Infinity,0.}}".
I looked at the explanations of the error message and there it was suggested to give a particular value to x and to compute the integral for that particular value. I gived one particular value and I obtained the expected result. Anyway I need to obtain an analytical expression for all x>0.
My question is, how can be performed the integral and to obtain the analytical function F[x]?
Thank You in advance,
Kreig