Re: SetDelayed
- To: mathgroup at smc.vnet.net
- Subject: [mg92884] Re: SetDelayed
- From: Szabolcs Horvát <szhorvat at gmail.com>
- Date: Fri, 17 Oct 2008 05:21:49 -0400 (EDT)
- Organization: University of Bergen
- References: <gd7068$iba$1@smc.vnet.net>
Itzhak wrote:
> Why does Mathematica reply with:
>
> ..."Integrand [(x-Cos[y])/(1+x^2-2*x*Cos[y])^1.5 is not numerical at {y}={1.5708}", to the following:
>
> Clear[f]
> f[x_]:=NIntegrate[(x-Cos[y])/(1+x^2-2*x*Cos[y])^1.5,{y,0,Pi}];
> Plot[Evaluate[f[x],{x,0,2}]
>
Because you used Evaluate, and x is a symbol.
f[x_?NumericQ]:=NIntegrate[(x-Cos[y])/(1+x^2-2*x*Cos[y])^1.5,{y,0,Pi}];
Plot[f[x],{x,0,2}]