Re: problems plotting a derivative-- got the solution
- To: mathgroup at smc.vnet.net
- Subject: [mg54537] Re: problems plotting a derivative-- got the solution
- From: "J. K. Smith" <rob at pi-overe.com>
- Date: Tue, 22 Feb 2005 04:24:27 -0500 (EST)
- References: <cvc80j$qqu$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Two kind folks pointed out I should do
ParametricPlot[Evaluate[{D[f[x], x], x^2}], {x, 0, 1}]
and it works nicely. Thanks again
J. K. Smith wrote:
> I've tried a lot of ways but nothing has worked so far.
> The following statements are my problem simplified:
>
> f[x_] := 2x^3;
> ParametricPlot[{D[f[x], x], x^2}, {x, 0, 1}]
>
> When I run this I get error messages griping about numbers not being
> valid variables but it doesn't end up plotting anything. In this example
> I should see a straight line.
>
> I've tried using Evaluate[ D[f[x],x] ] and lots of other schemes which
> seemed to work in the past but I can't get ParametricPlot to digest any
> of them. Something about the result of that derivative doesn't yield
> something that can be plotted. But I don't know what property it is.
>
> Would you kind Mathematica gurus please get me thru this one (too)?
>
> Thanks.
>
> remove the dash if emailing
>