Question

What is the pattern for terms of infinite sequence: 9, 18, 27, 36, 45, 54?

Answer 1

`a_n = 9n forall n in NN`

Explanation:

Notice that the sequence is: `9xx1, 9xx2, 9xx3, 9xx4, ....`

Hence, the sequence is `9xx(1,2,3,4, ....`

Let the `n^(th)` term of our sequence be `a_n`

So, `a_1 = 9` and `a_(n+1) = 9(n+1)`

Thus, `a_n =9n forall n in NN` defines our infinite sequence.