Unfortunately that's not even correct for complex numbers: i is a square root of -1, and -i is the other. Complex numbers are really nice in that every non-zer

Unfortunately that's not even correct for complex numbers: i is a square root of -1, and -i is the other. Complex numbers are really nice in that every non-zero complex number has two square roots, three cube roots, four fourth roots, etc. A better definitional statement is the other way around: i has the property that i^2 = -1.