mathematics Functions A function \(f\) from a set \(D\) to a set \(Y\) is a rule that assigns a unique value \(f(x)\) in \(Y\) to each \(x\) in \(D\). The set \(D\) of all

mathematics Quadratic Equations When \(a \ne 0\) , there are two solutions to \(ax^2 + bx + c = 0\) and they are $$x = {-b \pm \sqrt{b^2-4ac} \over 2a}.$$ Discriminant: \(D = b^2-4ac\) If \(\alpha\) and \(\beta\