What is the 8th term of a geometric sequence for which a1= 3 and a2 =9? a8 = ?

Answer 1

Geometric sequences are defined by a set of numbers multiplied by a common factor. Between a₁ and a₂, we go from 3 to 9, meaning our multiple should be 3.

Since our initial value is ALSO our multiple, we can use the equation:

a_n = 3ⁿ

which means a₈ = 3⁸ = 6,561