I am using CliffsNotes QuickReview Algebra I (which by the way I find to be fantastic, except that it is very prone to typos) to review the algebra that I haven't learned in almost a decade. It says there that (x^2)^1/2 = |x|, but it also says that (x^2)^1/2 = +-x. But isn't it true that |x| > 0? So how can |x| = +-x? Someone please help me understand this. Thanx.