Unset (Built-in Mathematica Symbol)

lhs =. removes any rules defined for lhs.

ZeroTest (Built-in Mathematica Symbol)

ZeroTest is an option to various linear algebra functions that gives a function to use in testing whether symbolic expressions should be treated as zero.

$BatchOutput (Built-in Mathematica Symbol)

$BatchOutput is True if output in the current session is being sent in batch mode, suitable for reading by other programs.

$HistoryLength (Built-in Mathematica Symbol)

$HistoryLength specifies the number of previous lines of input and output to keep in a Mathematica session.

$Language (Built-in Mathematica Symbol)

$Language is a list of strings which give the names of languages to use for messages.

$MinNumber (Built-in Mathematica Symbol)

$MinNumber gives the minimum positive arbitrary-precision number that can be represented on a particular computer system.

$ScriptCommandLine (Built-in Mathematica Symbol)

$ScriptCommandLine is a list of strings giving the elements of the command line with which the standalone Mathematica script was invoked.

$TimeUnit (Built-in Mathematica Symbol)

$TimeUnit gives the minimum time interval in seconds recorded on your computer system.

Complex Numbers (Mathematica Tutorial)

You can enter complex numbers in Mathematica just by including the constant I, equal to Sqrt[-1]. Make sure that you type a capital I. If you are using notebooks, you can ...

Euler and Legendre Equations (Mathematica Tutorial)

An Euler equation has the general form Euler equations can be solved by transforming them to equations with constant coefficients. This is an example of an Euler equation.