# Imaginary Number

An Imaginary Number is a Number that is based on a real number multiplied by an imaginary unit.

## References

### 2014

• (Wikipedia, 2014) ⇒ http://en.wikipedia.org/wiki/Imaginary_number Retrieved:2014-10-16.
• An imaginary number is a number that can be written as a real number multiplied by the imaginary unit ,[note 1] which is defined by its property . [1] The square of an imaginary number is . For example, is an imaginary number, and its square is . Except for 0 (which is both real and imaginary [2] ), imaginary numbers produce negative real numbers when squared. An imaginary number can be added to a real number to form a complex number of the form , where the real numbers and are called, respectively, the real part and the imaginary part of the complex number.[note 2] Imaginary numbers can therefore be thought of as complex numbers whose real part is zero. The name "imaginary number" was coined in the 17th century as a derogatory term, as such numbers were regarded by some as fictitious or useless. The term "imaginary number" now means simply a complex number with a real part equal to, that is, a number of the form .

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