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Patterns & Sequences

Arithmetic and geometric sequences, series, sigma notation and financial applications.

CAPS Aligned Grade 12 Focused Paper 1 Exam Revision
Tₙ = a + (n-1)d

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Key Concepts

Master these ideas before attempting exam questions.

Arithmetic Sequence

Each term increases by a constant difference d. General term: Tₙ = a + (n−1)d.

Geometric Sequence

Each term is multiplied by a constant ratio r. General term: Tₙ = a·rⁿ⁻¹.

Arithmetic Series

Sum of n terms: Sₙ = n/2(2a + (n−1)d) or Sₙ = n/2(a + l).

Geometric Series

Sum of n terms: Sₙ = a(rⁿ−1)/(r−1). If |r| < 1, infinite sum: S∞ = a/(1−r).

Sigma Notation

∑ notation is shorthand for a sum. Identify the general term and the range of values.

Core Formulas

Commit these to memory — they appear in almost every exam.

Arithmetic General Term
\[ T_n = a + (n-1)d \]
a = first term, d = common difference, n = term number.
Geometric General Term
\[ T_n = a \cdot r^{n-1} \]
a = first term, r = common ratio.
Sum to Infinity (|r| < 1)
\[ S_\infty = \frac{a}{1-r} \]
Only valid when the series converges, i.e., |r| < 1.

After This Topic You Will Be Able To

These are your learning targets for Patterns & Sequences.

Identify arithmetic vs. geometric sequences
Find any term using the general term formula
Calculate sums of finite series
Apply the sum to infinity formula
Interpret and evaluate sigma notation

Common Exam Mistakes

Avoid these errors — they cost marks every year.

Using n instead of (n−1)

The formula is a + (n−1)d, not a + nd. Off-by-one errors lose marks.

Applying S∞ when |r| ≥ 1

The infinite sum formula only works if the series converges. Always check |r| < 1 first.

Confusing arithmetic and geometric

Check the pattern: constant difference (arithmetic) vs. constant ratio (geometric).

Downloadable PDF Resources

Free CAPS-aligned study materials for Patterns & Sequences.

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Study Notes
Patterns & Sequences Summary Notes

Comprehensive CAPS-aligned notes covering all key concepts, theorems, and worked examples for Patterns & Sequences.

PDF • CAPS Aligned • Grade 12
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Exam Questions
Patterns & Sequences Exam Questions + Memo

NSC-style exam questions with full memorandum. Ideal for timed practice and self-assessment before exams.

Includes Memo • CAPS Aligned
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Practice Set
Patterns & Sequences Structured Practice Set

Graded practice questions organised by difficulty. Perfect for building confidence before Paper 1.

Graded Difficulty • Grade 12
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Frequently Asked Questions

Straight answers to common Grade 12 CAPS questions about Patterns and Sequences.

What are Patterns and Sequences in Grade 12 Maths?

Patterns and Sequences in Grade 12 CAPS covers arithmetic sequences, geometric sequences, series, and sigma notation. You learn how to identify patterns, find terms, and calculate sums.

How do I improve at sequence questions?

Start by deciding whether the pattern is arithmetic or geometric, then use the correct formula carefully. Regular practice helps you recognise the structure of questions much faster.

What mistakes should I avoid in Patterns and Sequences?

Common mistakes include mixing up arithmetic and geometric formulas, using the wrong term number, and confusing the nth term with the sum formula. Careless calculator input also causes errors.

How do Patterns and Sequences appear in CAPS exams?

CAPS exams usually test nth term, sum formulas, sigma notation, and practical pattern questions. These questions are common in Paper 1 and often connect to algebraic reasoning.

Need Help with Patterns & Sequences?

Book a focused session with Chris Khomo and work through this topic step by step — at your own pace, online, from anywhere in South Africa.

Chris Khomo