Imaginary numbers? o.O

How do we use imaginary numbers?

Sometimes in Trigonometry, one will have a square root that is negative.

Some thing like this. 

*I know.

* Commonly used in Quadratic Formulas, Imaginary numbers are used to simplify a square root though it is (negative).

*By using an [i] you are able to identify its square or if irrational its simplified form.

*Remember the square root is considered a real number [-36], and [6i] is imaginary

6i

Now one can get something like this, which is irrational.  

         

√-18

√-1 • √18

(√18 = 9•2 = 3•3•2)

i • 3√2

[3i √2]   

 Courtesy of  http://www.regentsprep.org/Regents/math/algtrig/ATO6/SquareRootLes.htm