To represent the geometric sequence 6, 18, 54, ..., we need to identify the first term and the common ratio.
- The first term of the sequence is \( a = 6 \).
- The common ratio \( r \) can be found by dividing the second term by the first term: \[ r = \frac{18}{6} = 3 \]
- The general form for the \( n \)-th term of a geometric sequence can be defined as: \[ a_n = a \times r^{n-1} \] where \( a \) is the first term, \( r \) is the common ratio, and \( n \) is the term number.
Putting it all together, the function to represent the geometric sequence is: \[ f(n) = 6 \cdot 3^{n-1} \]
Thus, the correct response is: \[ f(x) = 6(3)^{x - 1} \]
So the answer is: f(x)=6(3)x−1