Question

Consider the arithmetic sequence (87, 83, 79,75...)

A. Find common difference, d
B. Find explicit formula

Answer 1

see explanation

Explanation:

A

the common difference d of the arithmetic sequence is

d = a₂ - a₁ = 79 - 83 = - 4

B

the explicit formula of an arithmetic sequence is

`a_(n)` = a₁ + (n - 1)d

where a₁ is the first term and d the common difference

here a₁ = 83 and d = - 4 , then

`a_(n)` = 83 - 4(n - 1) = 83 - 4n + 4 = 87 - 4n