Standard ANSI SQL. The key is that "^" is NOT the exponent operator as many (including myself) have assumed and as it is in VB. Rather it is the bitwise XOR operator, as in C#, which of course gives completely different results. That is standard ANSI.

Square Root functions require non-negative inputs in virtually every production language ever, except those that have built-in complex numbers, like Fortan and ADA.