Imran and Aubrey were asked to find an explicit formula for the sequence 14,5,−4,−13,…, where the first term should be g(1).Imran said the formula is g(n)=14−9(n−1).Aubrey said the formula is g(n)=14−9n.Which one of them is right?Choose 1 answer:(A) Only Imran(B) Only Aubrey(C) Both Imran and Aubrey(D) Neither Imran nor Aubrey
Q. Imran and Aubrey were asked to find an explicit formula for the sequence 14,5,−4,−13,…, where the first term should be g(1).Imran said the formula is g(n)=14−9(n−1).Aubrey said the formula is g(n)=14−9n.Which one of them is right?Choose 1 answer:(A) Only Imran(B) Only Aubrey(C) Both Imran and Aubrey(D) Neither Imran nor Aubrey
Identify sequence type: Identify the type of sequence. The sequence 14,5,−4,−13,extellipsis has a constant difference between consecutive terms, which means it is an arithmetic sequence.
Determine common difference: Determine the common difference d of the sequence. The difference between the first term 14 and the second term 5 is 5−14=−9. This is the common difference.
Use arithmetic sequence formula: Use the arithmetic sequence formula to find the nth term: g(n)=g(1)+(n−1)d. The first term g(1) is 14, and the common difference d is −9.
Substitute values into formula: Substitute the values of g(1) and d into the formula. The formula becomes g(n)=14+(n−1)(−9), which simplifies to g(n)=14−9(n−1).
Compare with provided formulas: Compare the derived formula with the formulas provided by Imran and Aubrey. Imran's formula is g(n)=14−9(n−1), which matches the formula we derived. Aubrey's formula is g(n)=14−9n, which does not match because it does not account for the first term being 14 when n=1.
More problems from Write a formula for an arithmetic sequence