Sequences and Series
Ages 16–18Difficulty adapts to you
Sequences and Series
An arithmetic sequence changes by a constant difference; a geometric sequence changes by a constant ratio. Use the nth-term rule to find a particular term and a sum formula when terms are added.
Your goals
- ✓You can find rules for arithmetic and geometric sequences and calculate sums.
- ✓You can use Sequences and Series, model correctly.
- ✓You can use the definitions, units, assumptions, and examples to check your answer.
Words to know
- Sequences and Series:
- Find rules for arithmetic and geometric sequences and calculate sums.
- model:
- A rule or representation used to describe a situation and make a prediction.
Examples
- 1For 5, 8, 11, ..., the nth term is 3n + 2.
- 2For 2, 6, 18, ..., the common ratio is 3 and the fourth term is 54.
Check these
- • Do not skip the meaning of a term or give a result without explaining what it means.
- • Keep every number, symbol, label, and unit in its correct place.
- • Show enough working to check how you reached your answer.
Helpful habits
- • Read the whole question before choosing what to do.
- • Show one clear step at a time and check each step.
- • If you are stuck, draw a model, try smaller numbers, or revisit the example.
Now try your own
Create your own sequences and series example, solve it, and explain how you checked it.
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