Question

An arithmetic

sequence is defined
recursively by
an= an-1 - 5.5. The
first term of the
sequence is 7.5. Write
the explicit formula
for the sequence.

Answer 1

an = 7.5 - 5.5(n - 1).

Explanation:

The common difference d = -5.5.

The first term is given as 7.5.

Explicit formula is

an = a1 + (n - 1)d

= 7.5 + (n - 1)-5.5

= 7.5 - 5.5(n - 1)