Question

Find the first 5 terms of the sequence defined by the formula \(u_{n}=3 n+6\).

Answer 1

\(u_{1}=3 \times 1+6=9\) \(u_{2}=3 \times 2+6=12\) \(u_{3}=3 \times 3+6=15\) \(u_{4}=3 \times 4+6=18\) \(u_{5}=3 \times 5+6=21\) So the sequence is \(9,12,15,18,21, \ldots\)
Note that the terms of the sequence increase by 3 each time and that the formula contains a ' \(3 n\) '.