Write an explicit formula for the sequence - 4, 1, 6, 11, ...

an = - 4 + 5 (n+1)

an = - 4 + 5 (n-1)

an = - 4 + (n-1)

an = - 4 + 5n

An = - 4 + 5 (n+1) A I Think

This is an arithmetic sequence because each term is 5 more than the previous term, the defining characteristic of an arithmetic sequence which is called the common difference. All arithmetic sequences can be expressed as:

a (n) = a+d (n-1), a=1st term, d=common difference, n=term number, in this case a=-4 and d=5 so

a (n) = - 4+5 (n-1)