Cambridge IGCSE Additional Mathematics · Syllabus 0606 · Quadratic Functions
Quadratic Formula
What is Quadratic Formula?
The general solution of ax^2 + bx + c = 0, giving x equal to negative b plus or minus the square root of b squared minus 4ac, all over 2a. It is supplied in the Cambridge 0606 List of formulas, so it need not be memorised, but it must be applied correctly: every coefficient carries its own sign, the whole numerator is divided by 2a, and the quantity under the root is the discriminant, so a negative value there means the equation has no real roots and the formula returns nothing.
This definition is part of the Quadratic Functions chapter in Cambridge IGCSE Additional Mathematics.