>>>No argument on that. But i=sqrt(-1) is what is (at least when I taught math) commonly used as a tool to explain to 'non-math' people what the imaginary part of a non-real quadratic solution is...
>>
>>Weeeeellll... You can always try to explain to non-math people (like me) what is an "imaginary part of a non-real quadratic solution" is... :-)
>
>See, I knew we should have a math section (s). Suppose you have a quadratic equation in x, and using the previous formula, you get the solution of x = 6 +/- sqrt(-5). The imaginary part is the sqrt(-5), often expressed as sqrt(5)i. 6 is the 'real' part. 'Imaginary' is sort of a term conjured up to indicate it can't be expressed on the real x/y plane...

On the other hand:
There's four fingers and a Thumb.