Algebra

Well for the problem

x² + 1 = 0

subtract 1 from both sides

x² = -1

square root both sides

x = ±√(-1)

so x = ±i

or x = 0 + 1i    or     x = 0 - 1i

As for the magnitude, I don't really know but I googled it and found some place that said when a complex number is written like this: " a + bi ", the magnitude is √(a² + b²).

So if that's right then the magnitude for this would be √(0² + 1²) = 1

I did this freshman year lol