So you start off with the given information:
\(b_{1}\) = 2
\(b_{n}\) = (\(b_{n-1}\))² + 1
Since you're looking for the 4th term, that would mean that you are looking for \(b_{4}\).
Since you know that we are looking for when n = 4, you can start with what we started off with, which is n = 1, to get to where n = 4.
When n = 1, b = 2,
when n = 2, b = 3,
when n = 3, b = 4,
when n = 4, b = 5.
So the fourth term, when n = 4, is 5.
