Q. Find an explicit formula for the arithmetic sequence −11,−3,5,13,…Note: the first term should be b(1).b(n)=□
Identify Sequence Type: Identify the type of sequence. The sequence −11,−3,5,13,… has a common difference between consecutive terms, indicating that it is an arithmetic sequence.
Calculate Common Difference: Calculate the common difference d of the sequence. To find the common difference, subtract the first term from the second term: d=−3−(−11)=−3+11=8.
Use Explicit Formula: Use the explicit formula for an arithmetic sequence, which is b(n)=b(1)+(n−1)d, where b(1) is the first term and d is the common difference. For this sequence, the first term, b(1), is −11 and the common difference, d, is 8.
Substitute Values: Substitute the values of b(1) and d into the formula to write an expression to describe the sequence. The expression for the sequence is b(n)=−11+(n−1)×8.
Simplify Expression: Simplify the expression. b(n)=−11+8n−8, which simplifies to b(n)=8n−19.
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