Why is the square root of a negative number impossible? What is the algorithm to get the square root of a number?
Why does it not accept / allow for negative numbers?
I've always been told that the square root of minus one does not exist by my maths teacher, but I don't really get why?

Any number times itself is a positive number (or zero), so you can't ever get to a negative number by squaring. Since square roots undo squaring, negative numbers can't have square roots.
