- a mathematical expression (a + bi) in which a and b are real numbers and i2 = −1.
Origin of complex number
First recorded in 1825–35
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- any number of the form a + i b, where a and b are real numbers and i = √–1See number (def. 1)
- A number that can be expressed in terms of i (the square root of -1). Mathematically, such a number can be written a + bi, where a and b are real numbers. An example is 4 + 5i.
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