## Wednesday, May 15, 2013

### Imaginary Numbers

As they used to say on the old Monty Python Flying Circus show, “And Now for Something Completely Different”!

Imaginary Numbers are not something that most of us run into, and only a small percentage of us will ever find a use for them in our jobs. They do come up as a topic in most Math Curriculums, however.

For those of us who have not had a math class in a long while, (or if you were not a Math Geek like me), an Imaginary Number is a number that can be written as a real number multiplied by the imaginary unit i. The Square of i is -1. An imaginary number has a negative or zero square. For example, 5i is an imaginary number, and its square is -25.

In terms of imaginary numbers, the Square Root of -4 is 2i.

Weird stuff, I know. Real-World applications can be found in Engineering and Scientific fields. They are nothing terribly new, as they were conceived as far back as the ancient Greeks (by a smart guy be the name of Heron of Alexandria).

Imaginary Numbers in Microsoft Excel

Interestingly enough, Excel can handle these quirks of the math world. It even has a couple of specially designed functions to deal with Imaginary and Complex (expressed in the form a + bi, where a and b are real numbers and i is the imaginary unit, where i2 = −1).

The Imaginary function operates with the syntax:
=IMAGINARY(inumber)

The Complex function uses this syntax:
=COMPLEX(realnumber, inumber, [syntax])

There are also several innate Excel tools for using imaginary numbers with your typical arithmetic functions of addition, multiplication, etc.

I suspect that I know what you may be thinking, “What does this have to do with me?”. Well, I wouldn’t be surprised if your son or daughter encounters Imaginary Numbers in school some time, and wouldn’t it Rock if you could show them how to do this in Excel?

He or she might even think you are pretty smart. Imagine that!