Question

4 Write a recursive formula for the sequence below.
f(1) = 3, f(2) = 7, f(3)=11, f(4)=15

Answer 1

aₙ = aₙ₋₁ + 4

Explanation:

Finding the common difference (d) :

• d = f(2) - f(1)
• d = 7 - 3
• d = 4

Hence, the recursive formula :

• aₙ = aₙ₋₁ + 4