Question

A sequence is defined recursively using the formula f(n + 1) = –0.5 f(n) . If the first term of the sequence is 120, what is f(5)

Answer 1

so the answer is 7.5?

Answer 2

lets substitute the values in the formula:
f(n + 1) = –0.5 f(n)

f(1) = 120
f(2) = -0.5*120 = -60
f(3) = -0.5(-60) = 30
f(4) = -0.5(30) = -15
f(5) = -0.5(-15) = 7.5