Write the first four elements of the sequence.
-$$\left( \frac { 1 } { 3 } \right) ^ { n }$$
A) $\frac { 1 } { 3 } , \frac { 1 } { 3 } , \frac { 1 } { 3 } , \frac { 1 } { 3 }$
B) $1 , \frac { 1 } { 3 } , \frac { 1 } { 9 } , \frac { 1 } { 27 }$
C) $\frac { 1 } { 3 } , \frac { 1 } { 9 } , \frac { 1 } { 27 } , \frac { 1 } { 81 }$
D) $\frac { 1 } { 3 } , - \frac { 1 } { 9 } , \frac { 1 } { 27 } , - \frac { 1 } { 81 }$

Question

Quizplus · Accepted Answer

Plugging in $n=1,2,3,$ and $4$ gives $\frac{1}{3},\frac{1}{9},\frac{1}{27},\frac{1}{81}$. The common ratio is $\frac{1}{3}$, so this is a geometric sequence. Thus, the first four terms are $\frac{1}{3}, \frac{1}{9}, \frac{1}{27}, \frac{1}{81}.$

Write the First Four Elements of the Sequence (13)n\left( \frac { 1 } { 3 } \right) ^ { n }(31​)n

Write the First Four Elements of the Sequence $\left( \frac { 1 } { 3 } \right) ^ { n }$