Given are the first three terms of a sequence that is geometric. Find a1 and r.
-$1 , - 3,9$
A) $a _ { 1 } = 1 ; r = 3$
B) $a _ { 1 } = 1 ; r = 1$
C) $a _ { 1 } = 1 ; r = - 3$
D) $a _ { 1 } = 1 ; r = - 4$

Question

Quizplus · Accepted Answer

In a geometric sequence, each term is the previous term multiplied by the common ratio $ r $. Here, $-3 = 1 \times r$ gives $r = -3$, and $9 = -3 \times r$ confirms $r = -3$. Thus, $a_1 = 1$ and $r = -3$.

Given Are the First Three Terms of a Sequence That 1,−3,91 , - 3,91,−3,9

Given Are the First Three Terms of a Sequence That $1 , - 3,9$