Question

A sequence of numbers a1, a2, a3, . . . is defined as follows: a1 = 3, a2 = 5, and every term in the sequence after a2 is the product of all terms in the sequence preceding it, e.g., a3 = (a1)(a2) and a4 = (a1)(a2)(a3). If an = t and n > 2, what is the value of an+2 in terms of t ?
(A) 4t (B) t^2 (C) t^3 (D) t^4 (E) t^8

Answer 1

Answer:

  (D)  t^4

Step-by-step explanation:

You have defined ...

  a3 = a2·a1

  a4 = a3·(a2·a1) = a3²

  a5 = a4·(a3·a2·a1) = a4² = (a3²)² = a3⁴

Then if a3 = t, a5 = t⁴