Re: Re: The graph of (x + 2)^(1/5) + 4 not plotted
- To: mathgroup at smc.vnet.net
- Subject: [mg103966] Re: [mg103962] Re: The graph of (x + 2)^(1/5) + 4 not plotted
- From: victor chg <kindlychung at gmail.com>
- Date: Wed, 14 Oct 2009 07:54:38 -0400 (EDT)
- References: <868306d90910120643u7f1c2299v2cd1845508dc85b7@mail.gmail.com>
This works, only the axes are not at normal positions, looks a bit strange: http://i38.tinypic.com/20f6ftg.png On Wed, Oct 14, 2009 at 11:22 AM, Mike Bryniarski <melondisco at gmail.com>wrote: > The link you posted does not seem to relate to your problem. you > wanted to show : > > Plot[ (x + 2)^(1/5) + 4 , {x, -4, 4}] > > I tried plotting the function in your subject and not surprisingly it > did not plot correctly. > the issue is taking the fifth root of x on Mathematica can result in a > complex number. (This can bee seen under possible issues on the Power > page in the documentation) > Example: > > in: (x + 2)^(1/5) + 4 /. x -> -3 > > out: 4 + (-1)^(1/5) > > The most obvious way (at least for me) to overcome this is to perform > some algebra on the function to eliminate the fractional power and > plot it in ContourPlot instead: > > ContourPlot[(y - 4)^5 == x + 2, {x, -4, 4}, {y, 0, 6}] > > This is the result I assume you were looking for. > > On Oct 13, 7:22 am, victor chg <kindlych... at gmail.com> wrote: > > Here is the link to the image:http://tinypic.com/view.php?pic=veae6u&s= > =4 <http://tinypic.com/view.php?pic=veae6u&s=%0A=4> > > > > Victor Chg > > -------------------------------------- > > Neuroscience Research Institute, Peking University, Beijing, P.R.China > > 100038 > > > -- -------------------------------------- Neuroscience Research Institute, Peking University, Beijing, P.R.China 100038
