Question

In which situation below would you want to use the Explicit Formula instead of the Recursive Formula?A) Find the 15th term when the first term is 7 and the common difference is-2.B) Find the 6th term when the first term is 2 and the common difference is 5.C) Find the 70th term when the first term is -1 and the common difference is 10.D) Find the 10th term when the first term is -3 and the common difference is 4.

Answer 1

A recursive formula allows us to find the n-th term in the sequence if we know the previous term in the secuence. In this case, it is easy to apply the recursive formula for cases a, b and d because the 15th, 6th and 10th are first terms in the series. However, it is more dificult to apply such formula for the 70th term. Hence, the answer is option C.