On Jan 18, 6:07 pm, Daniel Harris <[email protected]> wrote: > On Tue, Jan 18, 2011 at 10:51 PM, Robert Bradshaw > > > > > > <[email protected]> wrote: > > On Tue, Jan 18, 2011 at 2:35 PM, Daniel Harris > > <[email protected]> wrote: > >> Hello everybody > > >> I am just looking at sketching graphs and I came across a problem that > >> has me stumped. The graph I am trying to sketch is > > >> (x-3) / ( (x+1) * (x-2) ) > > >> now I have plotted the graph in sage on my TI-83 and at wolfram and > >> they all different. Now I am thinking is sage right and the others > >> wrong? or have I made an error inputting the equation? > > >> I would certainly welcome some help on the issue > > > What range are you plotting over? -1 < x < 1? -5 < x < 5? This could > > make a big difference on what the graph looks like. Likewise, what is > > the scale of the y-axis? I don't think Sage yet tries to remove the > > asymptotes at -1 and 2 from the plot. > > -1.5 < x < 3 the y peak at x=2 is the part that bothers me. It > doesnt seem to show up on my calc or wolfram alpha? >
This is really showing the asymptote. If you do sage: plot((x-3) / ( (x+1) * (x-2) ) ,(x,-1.5,3)) sage: plot((x-3) / ( (x+1) * (x-2) ) ,(x,-1.5,3),ymin=-10,ymax=10) you'll see what I mean. Unfortunately we don't have any 'guessing' for the vertical range. That's a bug and a feature at the same time :) A graphing calculator likely just picks something arbitrary for that. - kcrisman -- To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sage-support URL: http://www.sagemath.org
