h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Just clicked on your name, interesting.
You might like my home page poem.
What do you know about the square root of minus one?

Bad poetry is better than bad food, at least it won't kill!

As you probably know:

[If 'a' is a positive real number and 'n' a positive integer, there exists a unique positive real number 'x' such that 'xn' = 'a'. This number: "the (principal) nth root of a" is written 'n{sqroot a}'. The integer 'n' is called the index of the root. For 'n' = 2, the root is called the square root and is written {sqroot a}.]

The operative words here are 'positive' and 'real'. Minus-One may be 'one' but not 'the other'!
I leave it two you two work out which, but suffice it two say, trying two multiply to negatives in a real world can only give a positive. Two try with a negative and a positive defeats itself from the start by breaking the 'same' rule.

There is of course a theoretically answer which is available courtesy of A. Elk's Brackets Miss, brackets, brace of theories in... "I have a theory..." M.Python's F.C. 'All-England Summarize Proust Competition' (somewhere between 1969-74)...

Use your towel or visit:
http://www.geocities.com/~spanoudi/poems/index.html

..... Minus-One