To represent the geometric sequence 6, 18, 54, ... we first identify the common ratio and the first term.
- The first term \( a = 6 \).
- The common ratio \( r = \frac{18}{6} = 3 \).
The formula for the \( n \)-th term of a geometric sequence can be represented as:
\[ f(x) = a \cdot r^{(n-1)} \]
Where:
- \( a \) is the first term,
- \( r \) is the common ratio,
- \( n \) is the term number.
For this sequence, as \( x \) is typically treated as the term index starting from 1 (first term being \( x = 1 \)), we have:
\[ f(x) = 6 \cdot 3^{(x-1)} \]
Thus, the correct function that represents the given geometric sequence is:
f(x) = 6(3)^{x-1}
So the correct response is:
f(x) = 6(3)^{x-1}