Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n=1 for the first term.–13,–26,–39,–52,…an=_____
Q. Write an expression to describe the sequence below. Use n to represent the position of a term in the sequence, where n=1 for the first term.–13,–26,–39,–52,…an=_____
Identify type of sequence: Identify the type of sequence.We have: –13, –26, –39, –52, ...Is the given sequence geometric or arithmetic? Since there is a common difference between consecutive terms, the given sequence is arithmetic.
Determine first term and difference: Determine the first term (a1) and the common difference (d) of the sequence.The first term, a1=−13Common difference, d=−26−(−13)=−13
Write formula for nth term: Write the formula for the nth term of an arithmetic sequence. an=a1+(n−1)d
Substitute values into formula: Substitute the values of a1 and d into the formula.a1=−13d=−13an=−13+(n−1)(−13)
Simplify expression: Simplify the expression.an=−13−13(n−1)an=−13−13n+13an=−13n
More problems from Write variable expressions for arithmetic sequences