GCSE and A-level algebra
Quadratic functions revision checklist
Use this guide as a revision starting point, then practise with questions matched to your course and exam board.
A quadratic function has a highest power of two. Its graph is a parabola, and its roots are the x-values where the graph crosses the x-axis.
What to revise
- Expanding and factorising quadratic expressions.
- Solving by factorising, completing the square and the quadratic formula.
- Finding roots, the y-intercept and the turning point.
- Using the discriminant to determine the number of real roots.
b² − 4acPositive: two distinct real roots. Zero: one repeated real root. Negative: no real roots.