Junior Cycle · Sequences and Series ⏱ Tested in 2 exam questions since 2024 Lesson 4 of 5

JCHL Sequences and Series 4: General Term for a Quadratic Pattern

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You’ll learn

  • Every quadratic pattern can be written as Tn = an² + bn + c (this is learning work — it is NOT in the tables)
  • The second difference = 2a, so a = (second difference) ÷ 2
  • Find b and c with a simultaneous equation, using term 1 and term 2
  • Then write the full general term and you can find any term

Formula used

Tₙ = an² + bn + c

MUST LEARN

Most recent exam questions

  • 2024 JCHL Q12(b)
  • 2024 JCHL Q12(c)(i)

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