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0580/12 Feb/Mar 2024, Question 20: Quadratic and Cubic Sequences

Cambridge IGCSE Mathematics 0580 · Paper 12 (Core) · Calculator · 4 marks

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The question, in short

Use the given nth term rule n² − 3 to generate the first three terms, and find the nth term rule for the sequence 2, 9, 16, 23, 30.

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Part (a) · 2 marks

Substitute n = 1, 2 and 3 into n² − 3 to find the first three terms.

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

Answer−2 1 6

Part (b) · 2 marks

Find the nth term of the arithmetic sequence 2, 9, 16, 23, 30.

  1. 1Common difference = 7, so nth term = 7n + c
  2. 2n = 1: 7 + c = 2, c = −5
  3. 3nth term = 7n − 5

Answer7n −5

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Also searched as: 0580/12/F/M/24 · 0580_m24_qp_12 · 0580 m24 12 · question 20.
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