Write a formula for the general term (the nth term) of the geometric sequence.
-$2 , - 4,8 , - 16,32 , \ldots$
A) $a _ { n } = 2 ( - 2 ) ^ { n - 1 }$
B) $a _ { n } = a _ { 1 } - 2 ^ { n }$
C) $a _ { n } = 2 ( - 2 n )$
D) $a _ { n } = 2 ( - 2 ) ^ { n }$

Question

Quizplus · Accepted Answer

The sequence is geometric with the first term $a_1 = 2$ and common ratio $r = -2$. The formula for the nth term of a geometric sequence is $a_n = a_1 \cdot r^{n-1}$, which simplifies to $a_n = 2 \cdot (-2)^{n-1}$ for this sequence.

Write a Formula for the General Term (The Nth Term) 2,−4,8,−16,32,…2 , - 4,8 , - 16,32 , \ldots2,−4,8,−16,32,…

Write a Formula for the General Term (The Nth Term) $2 , - 4,8 , - 16,32 , \ldots$