Question

Guided Practice

A recursive formula for an arithmetic sequence is given. What is the explicit formula for this sequence?



a1=42an=an−1−6a subscript 1 baseline equals 42 line break a subscript n baseline equals a subscript n minus 1 baseline minus 6


A.
an=42+(n−1)(−6)a subscript n baseline equals 42 plus left parenthesis n minus 1 right parenthesis left parenthesis negative 6 right parenthesis


B.
an=42+(n−1)−(−6)a subscript n baseline equals 42 plus left parenthesis n minus 1 right parenthesis minus left parenthesis negative 6 right parenthesis


C.
an=−6+(n−1)42a subscript n baseline equals negative 6 plus left parenthesis n minus 1 right parenthesis 42

Answer 1

A.

an=42+(n−1)(−6)a subscript n baseline equals 42 plus left parenthesis n minus 1 right parenthesis left parenthesis negative 6 right parenthesis

Explanation:

42 is the first term and −6 negative 6 is the common difference.