Write an explicit formula for the sequence - 3, 1, 5, 9 ...

a. an = - 3 + 4 (n-1)

b. an = - 3 + 4n

c. an = - 3 + (n-1)

d. an = - 3 + 4 (n+1)

A. an = - 3 + 4 (n - 1)

Step-by-step explanation:

The sequence given follows an arithmetic progression. This means the following term can be gotten by simply adding a factor to the previous term (or even the first term).

They are represented by the equation:

y (n) = a + r (n - 1)

Where y (n) is the nth term

a = first term

r = factor

Let us compare this with the sequence given:

The first term, a, is - 3

We can get the factor, r, by using the second term, which is 1. This means n = 2.

=> 1 = - 3 + r (2 - 1)

1 = - 3 + r

=> r = 1 + 3 = 4

Therefore, putting a = - 3 and r = 4, the sequence can be written as:

y (n) = - 3 + 4 (n - 1)