Year 9 - Maths
Features of geometric sequences
Non-linear relationships
Study Hub
Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit we explore geometric and special number sequences like the Fibonacci sequence. We develop strategies to recognise types of sequence and continue them.
Lesson Summary
You will learn to appreciate the features of a geometric sequence.
Key Notes
- Arithmetic sequences are not the only type of sequence.
- In a geometric sequence, there is still a first term.
- Instead of a common difference, there is a common multiplier.
- This common multiplier is referred to as the common ratio.
Vocabulary To Learn
- Geometric sequence: A geometric sequence is a sequence with a constant multiplicative relationship between successive terms.
- Common ratio: A common ratio is a key feature of a geometric sequence. The constant multiplier between successive terms is called the common ratio.
Common Mistakes To Avoid
- After becoming very familiar with arithmetic sequences pupils can find the difference between the first two terms and just assume the sequence is arithmetic.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Arithmetic sequences are not the only type of sequence. In a geometric sequence, there is still a first term.
2. Use this key word in a maths sentence and explain it clearly. 'Geometric sequence'
A geometric sequence is a sequence with a constant multiplicative relationship between successive terms. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: After becoming very familiar with arithmetic sequences pupils can find the difference between the first two terms and just assume the sequence is arithmetic. Correction: Explore a large number of geometric and arithmetic sequences and see if pupils can articulate how they check if a sequence is geometric. They might say the terms of the sequence grow more quickly (for some geometric sequences).
More Lessons In This Unit
- Checking understanding of arithmetic sequences Study Guide
- Extrapolating a sequence Study Guide
- Features of special number sequences Study Guide
- Graphing special number sequences using technology Study Guide
- Problem solving with non-linear relationships Study Guide
- Recognising geometric sequences Study Guide
- Recognising special number sequences Study Guide
- Representing geometric sequences graphically Study Guide
- Securing understanding of arithmetic sequences Study Guide
Browse all guides in the Year 9 Maths guide library.