Re: ImplicitPlot errors

*To*: mathgroup at smc.vnet.net*Subject*: [mg75146] Re: ImplicitPlot errors*From*: "David Rees" <w3bdevilREMOVE at THISw3bdevil.com>*Date*: Wed, 18 Apr 2007 05:07:30 -0400 (EDT)*References*: <evvbfs$9q5$1@smc.vnet.net>

To all of those who replied, thanks, but I found the problem. I entered the equation as "2xy" rather than "2x*y", when I do that Mathematica has no complaint. I also had a problem with an equation involving Euler's constant, I thought the "e" character (or the stylised "e" symbol in the toolbox) automatically represented Euler's constant in this context. My bad, I didn't realise it was uppercase "E" (my calculator, a Ti-83 uses uppercase E to define Power 10 exponents and lowercase e for Euler's). Once again, thanks. "David Rees" <w3bdevilREMOVE at THISw3bdevil.com> wrote in message news:evvbfs$9q5$1 at smc.vnet.net... > Hi, > > I've been trying to get ImplicitPlot to plot an implicit function > (naturally > ;) ), but it throws errors to cryptic for me, even when copying and > pasting > from the Mathematica function reference. > > In[40]:= ImplicitPlot[{x^2 + x*y + y^2 == 7, y == 2*Sqrt[7/3]}, {x, -5, > 5}] > > ImplicitPlot::var : > > Equation x^2+x > Function[x,x^2+2xy-3y^2-16]+Function[x,x^2+2xy-3<<1>>-16]^2==7 does not > have > a single variable other than x > > ImplicitPlot::var : > > Equation Function[x,x^2+2xy-3y^2-16]==2Sqrt(7/3) does not have a single > variable other than x > > Out[40]:=\!\(ImplicitPlot[{x\^2 + x\ Function[x, x\^2 + 2\ > xy - 3\ y\^2 - 16] + Function[ > x, x\^2 + 2\ xy - 3\ y\^2 - 16]\^2 == 7, Function[x, x\^2 + > 2\ > xy - 3\ y\^2 - 16] == 2\ \@\(7\/3\), x == 2\ \@\(7\/3\)}, {x, > \ > \(-5\), 5}, {Function[x, x\^2 + 2\ xy - 3\ y\^2 - 16], \(-5\), 5}]\) > > > > What am I doing wrong? Even ImplicitPlot[x+y==2,{x,-4,4}] fails. > > Thanks > > >