<P> A lesser known quadratic formula, as used in Muller's method, and which can be found from Vieta's formulas, provides the same roots via the equation: </P> <Dl> <Dd> x = − 2 c b ∓ b 2 − 4 a c . (\ displaystyle x = (\ frac (- 2c) (b \ mp (\ sqrt (b ^ (2) - 4ac)))).) </Dd> </Dl> <Dd> x = − 2 c b ∓ b 2 − 4 a c . (\ displaystyle x = (\ frac (- 2c) (b \ mp (\ sqrt (b ^ (2) - 4ac)))).) </Dd> <Ul> <Li> Roots and y - intercept in red </Li> <Li> Vertex and axis of symmetry in blue </Li> <Li> Focus and directrix in pink </Li> </Ul>

What is the formula of a quadratic equation