Re: Not all points plot on my graph...
- To: mathgroup at smc.vnet.net
- Subject: [mg105185] Re: Not all points plot on my graph...
- From: "Sjoerd C. de Vries" <sjoerd.c.devries at gmail.com>
- Date: Tue, 24 Nov 2009 05:45:32 -0500 (EST)
- References: <hedte4$lsn$1@smc.vnet.net>
Just try f[-3]//N. You'll see it's imaginary (one of the three
possible roots).
Cheers -- Sjoerd
On Nov 23, 1:59 pm, davef <davidfrick2... at yahoo.com> wrote:
> Why is it when I write this...
>
> Clear[f, x]
> f[x_] = (x + 2)^(2/3)
> Plot[f[x], {x, -3, 0}, PlotRange -> {{-3, 0}, {-4, 4}}]
> f[-3]
>
> .. I get no values show in the graph for x<-2 even though f[-3]
> evaluates to (-1)^(2/3).
>
> (-1)^(2/3) evaluates as f[-3]=1 so why wouldn't the point (-3,1) plot
> on my graph?