The first four terms of a sequence are shown below: 9, 5, 1, −3 Which of the following functions best defines this sequence? 1. f(n) = 5(n-1) + 9; for n ≥ 1
2. f(n) = − 5(n-1) + 9; for n ≥ 1
3. f(n) = − 4(n-1) + 9; for n ≥ 1
4. f(n) = 4(n-1) + 9; for n ≥ 1