#1**+2 **

There is no real answer, YOu cannot find the squareroot of a negative number but if you know about complex numbers there is an imaginary answer.

\(x^2=-1\\x=\pm i\)

Melody
May 17, 2017

#3**+1 **

The +- symbol means that the number can be both positive and negative. So, to elaborate on Meoldy's answer, x = -i **and ** x = +i. You use it whenever you take the square root of a number, as both (-x)^2 and (x)^2 give the same result, without exception.

You'll see this in the quadratic formula: \(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)

That just means there are two answers, one where the +- sign is positive and one where it's negative.

ThisGuy
May 17, 2017