Arithmetic/Types of Numbers/Imaginary Number

Imaginary Number

An imaginary number is a number whose square is less than zero.

e.g.

$i=\sqrt{-1}$

Conjugate Number

$-i=-\sqrt{-1}$

Rules

1) i + i = 2i

2) i - i = 0

3) i x i = i²

4) i / i = 1

5) i + (-i) = 0

6) i - (-i) = 2i

7) i x (-i) = -i² = 1

8) i / (-i) = -1