Question

1) Find a formula for a sub n for the arithmetic sequence a sub 1 = 7, d = 12.

2) Write the first 5 terms of the geometric sequence a sub 1 = 2, r = 2.

Answer 1

Explanation:

nth term = a₁ + (n-1)d = 7 + (n-1)12

:::::

nth term = a₁rⁿ⁻¹ = 2×2ⁿ⁻¹ = 2ⁿ

a₁ = 2

a₂ = 4

a₃ = 8

a₄ = 16

a₅ = 32