For ax² + bx + c = 0:
x = (-b ± √(b² - 4ac)) / 2a
What each letter means:
- a = coefficient of x² (number in front of x²)
- b = coefficient of x (number in front of x)
- c = constant term (the number on its own)
The ± symbol means you do TWO calculations: once with + and once with -. This gives your two solutions!
This key facts covers THE Formula (Given on the Formula Sheet!) within Quadratic Formula for GCSE Mathematics. Revise Quadratic Formula in Algebra for GCSE Mathematics with 11 exam-style questions and 5 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 8 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.
Practice questions for Quadratic Formula
For the equation 3x² − 5x + 2 = 0, what are the values of a, b, and c in the quadratic formula?
Explain what the value of the discriminant (b² − 4ac) tells you about the solutions to a quadratic equation.