Q. Complete the recursive formula of the arithmetic sequence13,6,−1,−8,…. c(1)=c(n)=c(n−1)+
Identify common difference: Identify the common difference in the sequence by subtracting any term from the term that follows it. The sequence is 13,6,−1,−8,extellipsis Subtract the second term from the first term to find the common difference: 6−13=−7.
Verify common difference: Verify the common difference by subtracting another pair of consecutive terms to ensure consistency. Subtract the fourth term from the third term: −8−(−1)=−7. The common difference is consistent, so it is −7.
Write recursive formula: Write the recursive formula for the arithmetic sequence using the common difference. The recursive formula has the form c(n)=c(n−1)+d, where d is the common difference. Since we have found that d=−7, the recursive formula is c(n)=c(n−1)−7.
State initial term: State the initial term of the sequence in the recursive formula. The first term of the sequence, c(1), is given as 13. So the complete recursive formula is c(1)=13, c(n)=c(n−1)−7 for n > 1.
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