Level:
Project ID:
1003084909
Accepted:
1
Clonable:
0
Easy:
1
We were given an oscillating sequence \( 3\text{, }-3\text{, }\ 3\text{, }-3\text{, }\ 3\dots \) (numbers \( 3 \) and \( -3 \) alternate regularly). What is the formula for the $n$th element of the sequence?
\( a_n=(-1)^{n+1}\cdot3\text{, }\ n\in\mathbb{N} \)
\( a_n=(-1)^{n}\cdot3\text{, }\ n\in\mathbb{N} \)
\( a_n=3^n\text{, }\ n\in\mathbb{N} \)
\( a_n=-3^n\text{, }\ n\in\mathbb{N} \)