Key Concepts in Quadratics
- Factorising quadratics
- Completing the square
- Quadratic formula
- Sketching quadratic graphs
- Solving quadratic equations
Exam Tips for Quadratics
- 💡Try factorising first — it is quickest if it works
- 💡Use the quadratic formula when the equation does not factorise
- 💡For completing the square: (x + b/2)² - (b/2)² + c
Exam Board Coverage
Quadratics appears on all major GCSE Maths exam boards at both Foundation and Higher tier.
AQA
Edexcel
OCR
Frequently Asked Questions
When should I use the quadratic formula?
Use the quadratic formula x = (−b ± √(b²−4ac)) / 2a when a quadratic equation cannot be factorised, or when decimal answers are required.
What is the discriminant?
The discriminant is b²−4ac. If it is positive, there are 2 real roots; if zero, 1 repeated root; if negative, no real roots.