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Which recursive formula can be used to define this sequence for n > 1?\newline\newline2,6,10,14,18,22,2, 6, 10, 14, 18, 22, \ldots\newline\newlineChoices:\newline(A)an=an1+an1+4a_n = a_{n-1} + a_{n-1} + 4\newline(B)an=73an1a_n = \frac{7}{3}a_{n-1}\newline(C)an=an14a_n = a_{n-1} - 4\newline(D)an=an1+4a_n = a_{n-1} + 4

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Q. Which recursive formula can be used to define this sequence for n>1n > 1?\newline\newline2,6,10,14,18,22,2, 6, 10, 14, 18, 22, \ldots\newline\newlineChoices:\newline(A)an=an1+an1+4a_n = a_{n-1} + a_{n-1} + 4\newline(B)an=73an1a_n = \frac{7}{3}a_{n-1}\newline(C)an=an14a_n = a_{n-1} - 4\newline(D)an=an1+4a_n = a_{n-1} + 4
  1. Determine Type: Determine if the sequence is arithmetic or geometric.\newlineWe need to check if the difference between consecutive terms is constant (which would make it an arithmetic sequence) or if the ratio between consecutive terms is constant (which would make it a geometric sequence).\newlineLooking at the sequence: 2,6,10,14,18,22,2, 6, 10, 14, 18, 22, \ldots, we can see that the difference between consecutive terms is constant.\newline62=46 - 2 = 4, 106=410 - 6 = 4, 1410=414 - 10 = 4, etc.\newlineThis indicates that the sequence is arithmetic.
  2. Find Difference: Find the common difference of the sequence.\newlineTo find the common difference, we subtract any term from the term that follows it.\newlineUsing the first two terms: 62=46 - 2 = 4.\newlineThe common difference (d)(d) is 44.
  3. Identify Formula: Identify the recursive formula for the given arithmetic sequence.\newlineSince the sequence is arithmetic with a common difference of 44, the recursive formula will involve adding 44 to the previous term.\newlineThe recursive formula should be of the form: an=an1+da_n = a_{n-1} + d, where dd is the common difference.\newlineSubstituting 44 for dd, we get: an=an1+4a_n = a_{n-1} + 4.
  4. Match with Choices: Match the recursive formula with the given choices.\newlineThe correct recursive formula we found is an=an1+4a_n = a_{n-1} + 4.\newlineComparing this with the given choices:\newline(A) a=a+a+4a = a + a + 4 (Incorrect, this does not make sense mathematically)\newline(B) a=73aa = \frac{7}{3}a (Incorrect, this suggests a geometric sequence)\newline(C) a=a4a = a - 4 (Incorrect, this would decrease the sequence by 44 each time)\newline(D) a=a+4a = a + 4 (Correct, this matches our formula)\newlineTherefore, the correct choice is (D) a=a+4a = a + 4.

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