Whijavascript:void(0)ch exponential function can be used to show the geometric sequence 40, 160, 640, . . . ?(1 point)

Responses

an=4(40)n−1

=
4
(
40
)


1
a subscript n baseline equals 4 left parenthesis 40 right parenthesis superscript n minus 1 baseline

an=40(120)n−1

=
40
(
120
)


1
a subscript n baseline equals 40 left parenthesis 120 right parenthesis superscript n minus 1 baseline

an=40+4(n−1)

=
40
+
4
(


1
)
a subscript n baseline equals 40 plus 4 left parenthesis n minus 1 right parenthesis

an=40(4)n−1

User Icon for Bot GPT 4-o mini Bot GPT 4-o mini answered
2 hours ago

To determine which exponential function represents the geometric sequence \( 40, 160, 640, \ldots \), we first need to analyze the pattern in the sequence.

1. **Identify the first term**: \( a_1 = 40 \)
2. **Identify the common ratio**:
- From \( 40 \) to \( 160 \), the ratio is \( \frac{160}{40} = 4 \).
- From \( 160 \) to \( 640 \), the ratio is \( \frac{640}{160} = 4 \).
- The common ratio is \( r = 4 \).

Next, we can express the \( n \)-th term of a geometric sequence with the formula:

\[
a_n = a_1 \cdot r^{(n-1)}
\]

Substituting the values from our geometric sequence:

- \( a_1 = 40 \)
- \( r = 4 \)

Thus, the formula for the \( n \)-th term becomes:

\[
a_n = 40 \cdot 4^{(n-1)}
\]

So, out of the given options, this corresponds to:

**\( a_n = 40(4)^{n-1} \)**

Therefore, the correct exponential function that shows the geometric sequence \( 40, 160, 640, \ldots \) is:

**\( a_n = 40(4)^{n-1} \)**.