if f (1) = - 5 and f (n) = f (n-1) + 7, find the first four terms and the common difference of the sequence

- 5, 2, 9, 16 and d = + 7

Step-by-step explanation:

to obtain the first four terms substitute n = 2, 3, 4 into the recursive formula

f (1) = - 5 ← given

f (2) = f (1) + 7 = - 5 + 7 = 2

f (3) = f (2) + 7 = 2 + 7 = 9

f (4) = f (3) + 7 = 9 + 7 = 16

common difference d = 16 - 9 = 9 - 2 = 2 - ( - 5) = 7