The film is often considered to be part of a trilogy with Leone's earlier films A Fistful of Dollars[?] and For a Few Dollars More[?].
... is 4a2. We get <math>\left(x+\frac{b}{2a}\right)^2=\frac{-4ac+b^2}{4a^2}=\frac{b^2-4ac}{4a^2}.</math> Taking square roots of both ...