Paper 1 · Algebra Lesson 23 of 23

Algebra 23 – Iterative equations

You’ll learn

  • Read recurrence notation: Uₙ, Uₙ₊₁, Uₙ₊₂ as consecutive terms
  • Verify a closed form Uₙ satisfies a recurrence using aⁿ⁺ᵏ = aⁿ·aᵏ
  • Collect 3ⁿ and 2ⁿ as separate like terms — never merge the bases
  • Find a term like U₆ by iterating the recurrence from the starting values

Formula used

First rule of powers

aᵖ⁺ᵍ = aᵖ · aᵍ

On page 21 of the log tables — read it off, don’t memorise.
Open the worked PDF

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