Question

A sequence has an initial term a1=22 and a recursive formula an=an−1−10.

What is the explicit formula for the sequence?

an=22+10(n−1)
an=22−10(n−1)
an=10−22(n−1)
an=10+22(n−1)

Answer 1

• B. aₙ = 22 - 10(n - 1)

Explanation:

Recursive formula:

• a₁ = 22
• aₙ = aₙ ₋₁ - 10
• Common difference is d = -10

Explicit formula:

• aₙ = a₁ + (n - 1)d = 22 + (n - 1)*(-10) = 22 - 10(n - 1)

Correct choice is B