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Re: Question: inequalities



Mike & Lizette Sullivan wrote:
> 
> Hello everyone, I am using Mathematica 2.2:
......
> For example, lets say I want to get mathematica to solve  Abs(2x+1)>5,
> where Abs means Absolute Value Of?
> 
> Does mathematica have the capability of giving me a solution set like
> (-Infinity, -3) U (2, Infinity) which is the solution to this problem?
> 
> Please help.
> 
> Mike Sullivan
> mliz@mingspring.com

Mike,

With Mathematica 3.x (I don't know if the package will work with 2.2)

<<Algebra`InequalitySolve`

?InequalitySolve

InequalitySolve[expr, x] gives the solution set of an
   expression containing logical connectives and univariate
   polynomial equations and inequalities in the variable x.
   InequalitySolve[expr, {x1, ..., xn}] gives the solution
   set of an expression containing logical connectives and
   linear equations and inequalities in the variables {x1,
   ..., xn}.


InequalitySolve[Abs[2x+1]>5,x]

x < -3 || x > 2

-- 
Allan Hayes
Training and Consulting
Leicester, UK
hay@haystack.demon.co.uk
http://www.haystack.demon.co.uk
voice: +44 (0)116 271 4198
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