This is documentation for Mathematica 3, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)
 Documentation / Mathematica / Add-ons / Standard Packages / Algebra  /

Algebra`InequalitySolve`

The package provides a function for solving systems of univariate inequalities. InequalitySolve[expr,x] finds conditions that must be satisfied by real values of x in order for the expression expr to be true. The expression should contain logical connectives and univariate polynomial equations and inequalities in the specified variable.


Finding solutions to inequalities.

  • This loads the package.
  • In[1]:= <<Algebra`InequalitySolve`

  • Here is a set of solutions to a polynomial inequality.
  • In[2]:= InequalitySolve[x (x^2 - 2) (x^2 - 3) > 0, x]

    Out[2]=

  • The inequalities may contain absolute values and rational functions.
  • In[3]:= InequalitySolve[x/Abs[x - 1] >= 0 && 1/x < x + 1, x]

    Out[3]=

  • Here the inequalities contain the exponential function. In general, if inequalities contain nonpolynomial functions of the specified variable, we may get an incorrect result.
  • In[4]:= InequalitySolve[Abs[x - 1] <= 5 && E^x <= 3, x]

    InequalitySolve::npi: A nonpolynomial equation or inequality encountered. The solution set may be incorrect.

    Out[4]=