Question

Given the recursive formula find the first 4 terms for each. (not multiple choice) (MAFS.912.F-BF.1.3) A. An=an-1 3 when a1=5 B. An=an-1 + 2/3 when a1=1 C. An=an-1 + 12 when a1=30

Answer 1

See explanations below

Explanation:

1) Given the recursive function An=an-1 + 3 when a1 = 5, we are to find the first four terms;

First term a1 = 5

a2 = a1 +3

a2 = 5 + 3

a2 = 8

a3 = a2 + 3

a3 = 8+3

a3 = 11

a4 = a3 + 3

a4 = 11 + 3

a4 = 14

The first four terms are 5, 8, 11 and 14

2) For the recursive function An=an-1 + 2/3 when a1 = 1

a2 = a1 + 2/3

a2 = 1 + 2/3

a2 = 5/3

a3 = a2 + 2/3

a3 = 5/3 + 2/3

a3 = 7/3

a4 = a3 + 2/3

a4 = 7/3 + 2/3

a4 = 9/3

a4 = 3

Hence the first four terms of the sequence are 2/3, 5/3, 7/3, 3

3) For the recursive function An=an-1 + 12 when a1=30

a2 = a1 + 12

a2 = 30 + 12

a2 = 42

a3 = a2 +12

a3 = 42 + 12

a3 = 54

a4 = a3 + 12

a4 = 54+12

a4 = 66

Hence the first four terms of the sequence are 30, 42, 54, 66