
Mark M. answered 05/19/20
Mathematics Teacher - NCLB Highly Qualified
Note that "real" numbers are no more "real" than "imaginary." They are both constructs.
One of several "reasons" is that the square of any "real" number is positive.
An example, x2 + 2 = 0 → x2 = -2, not possible with a "real" number. So we invent one (just like we invented "real" numbers). That number is i = √-1.
x2 = -2
x2 = (-1)(2)
x2 = i √2