Re: Vertical Tangents
- To: mathgroup at smc.vnet.net
- Subject: [mg25855] Re: Vertical Tangents
- From: Tom Moriarty <tjmor at erols.com>
- Date: Wed, 1 Nov 2000 01:25:40 -0500 (EST)
- References: <8t64dv$egv@smc.vnet.net> <yTLK5.273$km2.43693@ralph.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Once again I want to thank all those who responded to my question, your
suggestions certainly solved my problem.
Many thanks.
Albert Retey wrote:
> Tom Moriarty wrote:
> >
> > This group was very helpful on my last question and I hope you will be
> > willing to once again come to the aid of a teacher trying to illustrate
> > to calculus students tangents to implicit plots. By the way, I
> > purchased Mathematica on my own, it is not available to me at school -
> > so I plot at home and Xerox handouts for the kids. I have been able to
> > show them various implicit plots and tangents to them - for example
> > ImplicitPlot[{x^2 + x*y + y^2==7, y == 2*Sqrt[7/3]},{x,-5,5}] which
> > clearly shows the ellipse and one of the horizontal tangents (as asked
> > for in the textbook problem). But the problem also asked for the
> > vertical tangents, one of which would be x == 2*Sqrt[7/3], but I get the
> > message that this equation does not have a single variable other than
> > x. Is there any way to plot a vertical line?
>
> I don't have expericence with ImplicitPlot, so I don't know whether you
> can make it plot what you need, but a simple way to produce a vertical
> line is:
>
> p = ParametricPlot[{2*Sqrt[7/3], t}, {t, -10, 10}]
>
> Then use Show to put it together with your ImplicitPlots
>
> Albert