Question

Find the 12th term in the sequence: 1/16, -1/8, 1/4

Answer 1

Explanation:

hello :

the sequence is geometric because : (1/4)/(-1/8) = (-1/8)/(1/16)=-2 = r

the nth term is : An =A1 × r^(n-1)

a common ratio is : r and A1 the first term

in this exercice : r =2 A1 = 1/16

when : n =12 you have the 12rd term A12

A12 = 1/16 × 2^(12-1) = 1/16 × 2^(11)