Re: Plotting

*To*: mathgroup at smc.vnet.net*Subject*: [mg73024] Re: Plotting*From*: "dimitris" <dimmechan at yahoo.com>*Date*: Mon, 29 Jan 2007 04:51:40 -0500 (EST)*References*: <epfa83$doc$1@smc.vnet.net>

First have a look at the following links: http://library.wolfram.com/infocenter/Conferences/180/ http://library.wolfram.com/infocenter/Conferences/181/ http://library.wolfram.com/infocenter/Conferences/179/ Then f[x_] := x^3 - 16*x^2 + 3*x + 1 Plot[f[x], {x, -3, 20}, Axes -> {True, False}, AxesStyle -> GrayLevel[0.7], Frame -> {True, True, False, False}, FrameLabel -> TraditionalForm /@ {x, HoldForm[f[x]]}, FrameTicks -> {Range[-5, 20, 5], Range[-600, 800, 400]}, Epilog -> {Blue, AbsolutePointSize[6], (Point[{#1, 0}] & ) /@ (x /. NSolve[f[x] == 0])}, ImageSize -> 400]; On Jan 27, 12:41 pm, "Rayne" <ghcgw... at singnet.com.sg> wrote: > Hi all, > I want to plot the cubic equation f(x) == x^3 - 16x^2 + 3x + 1 == 0. I had: > > f==x^3-16 x^2+3 x+1 ==== 0 > Plot[f,{x,-1,20}] > > but I was unable to get the plot. The error message says > > Plot::plnr: f is not a machine-size real number at x == -0.999999. > Plot::plnr: f is not a machine-size real number at x == -0.148093. > Plot::plnr: f is not a machine-size real number at x == 0.780985. > General::stop: Further output of Plot::plnr > will be suppressed during this calculation. > > How do I get around this problem? > > Thank you. > > Regards, > Rayne