X in (-oo:+oo)
X^2 = 1/100 // - 1/100
X^2-(1/100) = 0
X^2-1/100 = 0
1*X^2 = 1/100 // : 1
X^2 = 1/100
X^2 = 1/100 // ^ 1/2
abs(X) = 1/10
X = 1/10 or X = -1/10
X in { 1/10, -1/10 }
