### Do you know J?

We all know that taking the square root of a negative number, such as the square root of -9 is simply the square root of +9, times i.  Where i is an imaginary number.  You can use this imaginary unit to solve equations with negative solutions.  But we are not worried about i, we are worried about j.  What is j?  What does it look like? What does it do?

With the development of higher math (polynomial rings) the concept behind an imaginary number became more substantial  but then one also finds other imaginary numbers such as the j of tessarines which has a square of +1.  The tessarines are a mathematical idea introduced by James Cockle in 1848.  The concept includes both ordinary complex numbers and split-complex numbers.

So if you think i is alone in the imaginary universe, don't forget the forgotten number j.