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.–39,–78,–117,–156,…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.–39,–78,–117,–156,…an=_____
Identify sequence type: Identify the type of sequence.We have: −39, −78, −117, −156, ...Is the given sequence geometric or arithmetic?−39, −78, −117, −156, ...Here, there is a common difference between consecutive terms.The given sequence is arithmetic.
Determine values of a1 and d: Determine the values of a1 and d of the sequence. The first term, a1=−39 Common difference, d=−78−(−39)=−39
Write nth term formula: Write the formula for the nth term of an arithmetic sequence.an=a1+(n−1)da1=−39d=−39Write an expression to describe −39,−78,−117,−156,...an=a1+(n−1)dan=−39+(n−1)(−39)
Simplify expression: Simplify the expression.an=−39+(−39n+39)an=−39n+39−39an=−39n
More problems from Write variable expressions for arithmetic sequences