Question

* WILL MEDAL *
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

You may have to write out the first 5 terms of this recursively-defined sequence. The first term is 120. That means that n = 1 and f(n)=120.
What's the next term? Let n = 2 and find it.