A quick recap, then the next step
You already master linear sequences — this year you meet quadratic ones.
In Grade 7 you became fluent with linear sequences. You can take , spot the common difference of 4, and write the nth-term rule almost on sight.
This year you go further. You will meet quadratic sequences — sequences whose rule contains an term — and learn the elegant method that unlocks them.
The big idea this year is analysis. Before you write any rule, you study the differences between terms. A constant first difference means linear. A first difference that itself changes steadily points to something new and more interesting.
Keep your Grade 7 toolkit close — every linear skill still applies, and quadratics build straight on top of it.
- A linear sequence has a constant first difference.
- A quadratic sequence has a rule with an term.
- Stage 9 focuses on analysing differences before choosing a rule.
- Quadratic work builds directly on your linear sequence skills.