Question

How can an expression or process be determined for an arithmetic sequence?

Answer 1

An aritmetic sequcne is represented as

$a_n=a_1+d(n-1)$

where
an=nth term
a1=first term
d=common differnce, or how much each term increases by
n=which term



example

1,3,5, etc
first term is 1
common difference is 2 because it increases by 2 each time
so the formula would be
$a_n=1+2(n-1)$

if we had
5,3,1
first term s 5
common difference is -2 since it goes up by -2 each time
so formula is
$a_n=5-2(n-1)$



hope this helps