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# complex variable

a variable to which complex numbers may be assigned as value.
[1875-80]

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In mathematics, a variable that can take on the value of a complex number.

In basic algebra, the variables x and y generally stand for values of real numbers. The algebra of complex numbers (complex analysis) uses the complex variable z to represent a number of the form a + bi. The modulus of z is its absolute value. A complex variable may be graphed as a vector from the origin to the point (a,b) in a rectangular coordinate system, its modulus corresponding to the vector's length. Called an Argand diagram, this representation establishes a connection between complex analysis and vector analysis. See also Euler's formula.

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Universalium. 2010.

### Look at other dictionaries:

• complex variable — com′plex var′iable n. math. a variable to which complex numbers may be assigned as value • Etymology: 1875–80 …   From formal English to slang

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