Q. {f(1)=−8f(n)=f(n−1)−3Find an explicit formula for f(n).f(n)=
Identify sequence type: Identify the type of sequence described by the function f(n). The function f(n)=f(n−1)−3 suggests that this is an arithmetic sequence because the difference between consecutive terms is constant.
Determine first term: Determine the first term of the sequence. We are given that f(1)=−8, so the first term, a1, is −8.
Find common difference: Determine the common difference of the sequence. The function f(n)=f(n−1)−3 indicates that the common difference, d, is −3 because each term is 3 less than the previous term.
Use explicit formula: Use the explicit formula for an arithmetic sequence, which is an=a1+(n−1)d. Substitute the values of a1 and d into the formula. In this case, a1=−8 and d=−3.
Write formula for sequence: Write the explicit formula for the sequence using the values from Step 4. The formula is f(n)=−8+(n−1)(−3).
Simplify the formula: Simplify the formula. f(n)=−8−3(n−1)=−8−3n+3=−3n−5.
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