Carlos and Ana were asked to find an explicit formula for the sequence −10,−4,2,8,…, where the first term should be f(1).Carlos said the formula is f(n)=−10+6n.Ana said the formula is f(n)=−10+6(n−1).Which one of them is right?Choose 1 answer:(A) Only Carlos(B) Only Ana(C) Both Carlos and Ana(D) Neither Carlos nor Ana
Q. Carlos and Ana were asked to find an explicit formula for the sequence −10,−4,2,8,…, where the first term should be f(1).Carlos said the formula is f(n)=−10+6n.Ana said the formula is f(n)=−10+6(n−1).Which one of them is right?Choose 1 answer:(A) Only Carlos(B) Only Ana(C) Both Carlos and Ana(D) Neither Carlos nor Ana
Identify sequence type and pattern: Identify the type of sequence and the pattern.The sequence given is −10,−4,2,8,… which increases by 6 each time. This indicates that it is an arithmetic sequence with a common difference (d) of 6.
Write explicit formula for arithmetic sequence: Write the general form of the explicit formula for an arithmetic sequence.The general form of the explicit formula for an arithmetic sequence is f(n)=a1+(n−1)d, where a1 is the first term and d is the common difference.
Determine first term of sequence: Determine the first term (a1) of the sequence.The first term given in the sequence is −10, so a1=−10.
Substitute values into formula: Substitute the values of a1 and d into the general formula.Substituting a1=−10 and d=6 into the formula gives us f(n)=−10+(n−1)6.
Simplify the formula: Simplify the formula.Simplifying the formula, we get f(n)=−10+6n−6, which further simplifies to f(n)=6n−16.
Compare formulas with Carlos and Ana: Compare the simplified formula to the formulas given by Carlos and Ana.Carlos's formula is f(n)=−10+6n, which is not the same as our simplified formula.Ana's formula is f(n)=−10+6(n−1), which simplifies to f(n)=6n−16, matching our simplified formula.
Determine correct formula: Determine which person is correct.Since Ana's formula matches the simplified formula we derived, Ana is correct. Carlos's formula does not match, so he is incorrect.
More problems from Write a formula for an arithmetic sequence