AlgebraKey Facts

THE Formula (Memorise This!)

Part of Quadratic Formula · GCSE GCSE Mathematics revision

This key facts covers THE Formula (Memorise This!) 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.

Topic position

Section 2 of 8

Practice

11 questions

Recall

5 flashcards

THE Formula (Memorise This!)

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!

Keep building this topic

Read this section alongside the surrounding pages in Quadratic Formula. That gives you the full topic sequence instead of a single isolated revision point.

When Factorising Fails Method: Using the Quadratic Formula Worked Example 1: Clean Numbers Worked Example 2: Surd Answer

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?

A. a = 3, b = 5, c = 2
B. a = 3, b = −5, c = 2
C. a = −5, b = 3, c = 2
D. a = 3, b = −5, c = −2

1 markfoundation

Explain what the value of the discriminant (b² − 4ac) tells you about the solutions to a quadratic equation.

2 marksstandard

Quick Recall Flashcards

The Quadratic Formula

x = (-b ± √(b² - 4ac)) / 2a

Quadratic Formula

x = (-b ± √(b²-4ac))/2a for ax² + bx + c = 0

11 questions on Quadratic Formula — practise free

Instant marking, adaptive difficulty, and 5 spaced repetition flashcards. Free until your GCSEs.

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When Factorising Fails

Method: Using the Quadratic Formula