Question

Write an explicit formula for the sequence -3, 1, 5, 9 ... i think the answer is a_n=-3+4(n-1) i just need someone to double check me :)

Answer 1

you are correct

Explanation:

The sequence has a common difference between consecutive terms

d = 9 - 5 = 5 - 1 = 1 - (- 3) = 4

This indicates the sequence is arithmetic with explicit formula

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

Here a₁ = - 3 and d = 4, thus

`a_(n)` = - 3 + 4(n - 1) = - 3 + 4n - 4 = 4n - 7