ah, so an aritmetic sequence can be written in form

where
is the nth term
is the first term
d is the common difference or how many times it increase or decreases each day
so an example:
Bob swims 2 miles on one day. Every day, he increases his distance by 0.2 miles. If he continues this pattern, how many miles will he swim on the 7th day?





bob swims 3.2 miles on the 7th term
also, you can use f(n) instead of
