Re: notation using # with exponents and &

*To*: mathgroup at smc.vnet.net*Subject*: [mg92927] Re: notation using # with exponents and &*From*: Bill Rowe <readnews at sbcglobal.net>*Date*: Mon, 20 Oct 2008 07:32:54 -0400 (EDT)

On 10/19/08 at 5:41 AM, molly_lipscomb at yahoo.com (Molly Lipscomb) wrote: >Hi, When I ask Mathematica to solve one of my equations, at first it >says that the response is long, and asks whether I want the full >output, or the output with a size limit. When I say that I want the >full output it comes up with seven roots, each of which has a >polynomial which is pages long. At the end of each root, it has a >notation which I haven't seen before and can't find in any >documentation--it has a box that looks something like a # sign, 1 >with an exponent, and then an & sign, a comma, and then a >number. Is this an abbreviation for something? What you probably got was a root object. The # and & are used to define pure functions. For example, #^2& is a pure function that squares its argument. The # is a slot that is filled by the function argument and the & is what makes this a function. >Does it mean that I don't have the full solution listed? No. >Also, I have been trying to get Mathematica to factor or simplify >the solution, but when I enter Factor[%], it just repeats the same >solution. Does this mean that the solution just can't be >simplified, or is there an alternative way to do this? It means Mathematica doesn't know how to factor the solution. That may or may not mean it cannot be factored. Note, I say factored since you said you used the function Factor. Factor will not necessarily result in the same output as using Simplify or FullSimplify. As to an alternative, I've no way to suggest one since you have not provided the Mathematica code leading to the output you are trying to simplify.