Complex Numbers in Polar Form
Modulus of a Complex Number
The modulus of a complex number is the length of the vector determined by the origin of its coordinates and affix. It is denoted by |z|.
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Argument of a Complex Number
The argument of a complex number is the angle that forms the vector with the real axis. It is denoted by arg(z).

Expression of a Complex Number in Polar Form
z = rα
|Z| = r r is the modulus.
arg(z) = ![]()
is the argument.
Examples
Express in polar form:
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z = 260º
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z = 2120º
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z = 2240º
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z = 2300º
Z = 2
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z = 20º
Z = −2
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z = 2180º
Z = 2i
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z = 290º
Z = −2i
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z = 2270º
Trigonometric form
rα = r (cos α + i sin α)
Examples
z = 2120º
z = 2 · (cos 120º + i sin 120º)
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z =10º = 1
z =1180º = −1
z =190º = i
z =1270º = −i