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Mathematica Teacher's Edition

Built-in Functions

Mathematical Functions

Numerical Functions

Arg

Arg[z] gives the argument of the complex number z.

Mathematical function (see Section A.3.10).
Arg[z] is left unevaluated if z is not a numeric quantity.
Arg[z] gives the phase angle of z in radians.
The result from Arg[z] is always between and .
Arg[z] has a branch cut discontinuity in the complex z plane running from to zero.
See The Mathematica Book on the web: Section 1.1.5 and Section 3.2.2.
See also: ArcTan, Sign.

Further Examples