Question

What is the explicit formula for this sequence

Answer 1

Answer:

A

Step-by-step explanation:

Start with the 3.

You know that there is a difference of 4 between (say) 2 and 5. The 3 is a sign that the sequence is increasing.  The members of the sequence are going up.

n - 1 means that the nth terms is calculated as an and uses the number of terms to be n-1. That means that the first term is a1 which is the starting point of the sequence.

The answer is an = a1 + (n-1)*d

d = 3

a1 = - 7

So let's try the formula out.

a4 = -7 + (4 - 1)*3

a4 = -7 + 3 * 3

a4 = -7 + 9

a4 = 2

Is 2 the 4th term in the series? Yes it is!