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0580/11 May/Jun 2023, Question 17: Quadratic and Cubic Sequences

Cambridge IGCSE Mathematics 0580 · Paper 11 (Core) · Calculator · 4 marks

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The question, in short

For a sequence defined by 10 − n², list its first three terms; for the sequence 7, 10, 13, 16, give a formula for its nth term.

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Part (a) · 2 marks

Using the rule 10 − n², work out the values of the first three terms.

  1. 1n = 1: 10 − 1² = 9
  2. 2n = 2: 10 − 2² = 6
  3. 3n = 3: 10 − 3² = 1
  4. 4First three terms: 9, 6, 1

Answer9, 6, 1

Part (b) · 2 marks

From the terms 7, 10, 13, 16, determine a formula giving the nth term.

  1. 1Common difference = 10 − 7 = 3, so the term is 3n + c
  2. 2n = 1: 3 × 1 + c = 7, so c = 4
  3. 3nth term = 3n + 4

Answer3n + 4

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Also searched as: 0580/11/M/J/23 · 0580_s23_qp_11 · 0580 s23 11 · question 17.
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