Question

I have x^2=2 how do you "undo" squaring a number?

Answer 1

You have to square root it. 

Answer 2

To undo the square you take the square root of both sides

$x^{2} =2$                                        equation
 
 $\sqrt{ x^{2} } = \sqrt{2}$               square root both sides

$x= \frac{+}{-} 1.41421356237$     x=1.4...