Re: Defining a function using common notation for absolute value (not Abs[x])

*To*: mathgroup at smc.vnet.net*Subject*: [mg112738] Re: Defining a function using common notation for absolute value (not Abs[x])*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Wed, 29 Sep 2010 04:11:51 -0400 (EDT)

The form |x| is simply not built-in, special input form that stands for Abs[x]. Probably it should be, along with the existing special input forms for square-root, etc. You could use the Notation package to make it work, but that's getting into advanced and somewhat dangerous territory. On 9/28/2010 6:06 AM, Gianni wrote: > Please refer to: > > http://www.accardi.com/tutor/AbsoluteValueNotationSnapShot.bmp > > Thanks in advance for any help here. > > > In ASCII: > > The given function to work with: f(x) = (3^-|x|) > > Define it in Mathematica: > > f[x_]:=3^-Abs[x] > > f[x_]:=3^-|x| > > Syntax::tsntxi: "|x|" is incomplete; more input is needed. > > Syntax::sntxi: Incomplete expression; more input is needed. > > I am trying to display the absolute value exponent in the second > function definition above in the way students will see it in a > standard math text (with the vertical bars, not Abs, like in the first > text line). The first definition above is without error (exponent > shown as -Abs[x]). The second is what I am trying to define without > error. I am trying to find the button (hopefully on the classroom > assistant palette) that will produce the desired results. The button > in the Typesetting section of the Classroom Assistant won't be > implemented as an error free function definition as you see in the > error messages. > > -------------------------------------------- > > > > > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305