Question

​ f(1)=−8 f(n)=f(n−1)−3 ​ Find an explicit formula for f(n)

Answer 1

f(n) = -8 -3(n -1)

Explanation:

The given recursive formula tells you that the difference between two sequential terms is -3, and that the first term is -8. This is a formula for an arithmetic sequence, so we can use the explicit formula ...

f(n) = a1 +d(n -1)

for a1 = -8 and d = -3.

f(n) = -8 -3(n -1)