The Imaginary Number is defined as
. However, for some reason engineers and physicists
prefer the symbol *j* to . Numbers of the form where and are Real Numbers are called Complex Numbers, and when is used to denote a Complex Number, it is
sometimes (in older texts) called an ``Affix.''

The Square Root of is

(1) |

(2) |

(3) |

(4) |

The Principal Value of is

(5) |

**References**

Courant, R. and Robbins, H. *What is Mathematics?: An Elementary Approach to Ideas and Methods, 2nd ed.*
Oxford, England: Oxford University Press, p. 89, 1996.

© 1996-9

1999-05-26