To represent the geometric sequence \(6, 18, 54, \ldots\), we first recognize the pattern in the sequence. The first term \(a_1\) is 6, and each subsequent term is obtained by multiplying the previous term by the common ratio, which is 3.
We can express the \(n\)-th term of a geometric sequence with the formula:
\[
a_n = a_1 \cdot r^{(n-1)}
\]
where \(a_1\) is the first term, \(r\) is the common ratio, and \(n\) is the term number.
In this case:
- \(a_1 = 6\)
- \(r = 3\)
Thus, the formula for the \(n\)-th term is:
\[
a_n = 6 \cdot 3^{(n-1)}
\]
If we define a function \(f(x)\) to represent the \(n\)-th term of the sequence, we can write:
\[
f(x) = 6 \cdot 3^{(x-1)}
\]
So the correct representation of the sequence as a function is:
\[
f(x) = 6(3)^{(x-1)}
\]
This matches the first option provided:
**Response:** \(f(x) = 6(3)^{x-1}\)