Question

Select ALL of the following that are examples of an arithmetic sequence. (1 point)
Responses

20, 14, 8, 2, −4, −10

3, 9, 27, 81, 243

You start at an elevation of 12,000 feet and climb down 1,000 feet per day.

You add $2 to a piggy bank and add triple the money you added the previous day for one month.

1, 11, 21, 25, 31, 38

Answers

Answer
Given the Recursive Formula:

a1 = 5

an = an−1 +2

(4 points)
What is the common difference? Response area

What is the first term? Response area

Which term of the sequence does a4
represent? Response area

Which term does an−1
represent? Response area

Answer
Given the explicit formula: an= 8 + 7(n − 1)
(4 points)
What is the common difference? Response area

What is the first term? Response area

What term is the formula finding if they ask for a5
? Response area

What value should replace n? Response area
Answer
Given the explicit formula, find the 5th term.

an = −5 +10(n − 1)


(1 point)
Responses


45

35

-25

10
Answer
Which function gives the correct recursive formula for the sequence?

2, 7, 12, 17, 22, 27


(1 point)
Responses

a1 = 7; an = an−1 + 2

a1 = 5; an = an −1 +2

a1 = 2; an = an −1 +5

a1 = 2; an = an −1 + 7
Answer
A car has 121,358 miles on its odometer and accumulates an average of 255 more each week. What is the function rule that represents the total number of M miles the car will have on the odometer after w weeks? (1 point)
Responses

M(w)=121,358w+255

M(w)=121,358w+255w

M(w)=121,358+255w

M(w)=121,358+255
Answered by GPT-4o mini
An arithmetic sequence is a sequence of numbers in which the difference between consecutive terms is constant. Let's evaluate each of the provided sequences:

1. **20, 14, 8, 2, −4, −10**: The differences between consecutive terms are
- 14 - 20 = -6,
- 8 - 14 = -6,
- 2 - 8 = -6,
- -4 - 2 = -6,
- -10 - -4 = -6.
This is an arithmetic sequence with a common difference of -6.

2. **3, 9, 27, 81, 243**: The differences between consecutive terms are
- 9 - 3 = 6,
- 27 - 9 = 18,
- 81 - 27 = 54,
- 243 - 81 = 162.
The differences are not constant; this is not an arithmetic sequence.

3. **You start at an elevation of 12,000 feet and climb down 1,000 feet per day**: This represents an arithmetic sequence where you decrease your elevation by a constant amount (1,000 feet) each day.

4. **You add $2 to a piggy bank and add triple the money you added the previous day for one month**: This is not an arithmetic sequence because the amount added each day is changing based on the previous day's addition (e.g., 2, 6, 18, ...).

5. **1, 11, 21, 25, 31, 38**: The differences between consecutive terms are
- 11 - 1 = 10,
- 21 - 11 = 10,
- 25 - 21 = 4,
- 31 - 25 = 6,
- 38 - 31 = 7.
The differences are not constant; this is not an arithmetic sequence.

From this evaluation, the examples of an arithmetic sequence are:

- **20, 14, 8, 2, −4, −10**
- **You start at an elevation of 12,000 feet and climb down 1,000 feet per day.**

So the correct responses are the first and third options.
Answered by GPT-4o mini
Let's analyze the recursive formula given:

1. **First term (a1)**:
- From the formula, we see that \( a_1 = 5 \).
- **Response**: **5**

2. **Common difference**:
- The recursive formula states that \( a_n = a_{n-1} + 2 \). The constant added (2) is the common difference.
- **Response**: **2**

3. **What term does \( a_4 \) represent?**:
- To find \( a_4 \), we can apply the recursive formula:
- \( a_1 = 5 \)
- \( a_2 = a_1 + 2 = 5 + 2 = 7 \)
- \( a_3 = a_2 + 2 = 7 + 2 = 9 \)
- \( a_4 = a_3 + 2 = 9 + 2 = 11 \)
- \( a_4 \) is the fourth term of the sequence.
- **Response**: **4th term**

4. **What does \( a_{n-1} \) represent?**:
- \( a_{n-1} \) is the term that comes before \( a_n \) in the sequence. Specifically, it represents the term that is one index before the \( n^{th} \) term, making it the \( (n-1)^{th} \) term.
- **Response**: **(n-1)th term**

To summarize the responses:
- Common Difference: **2**
- First Term: **5**
- \( a_4 \) represents: **4th term**
- \( a_{n-1} \) represents: **(n-1)th term**
Answered by GPT-4o mini
Let's analyze the explicit formula given:

\[ a_n = 8 + 7(n - 1) \]

1. **Common Difference**:
- The explicit formula for an arithmetic sequence is generally given by:
\[
a_n = a_1 + (n-1)d
\]
where \( d \) is the common difference. In your formula, \( d \) is the coefficient of \( (n - 1) \), which is 7.
- **Response**: **7**

2. **First Term**:
- To find the first term, substitute \( n = 1 \) into the formula:
\[
a_1 = 8 + 7(1 - 1) = 8 + 7 \cdot 0 = 8
\]
- **Response**: **8**

3. **What term is the formula finding if they ask for \( a_5 \)**:
- The notation \( a_5 \) refers to the 5th term of the sequence.
- **Response**: **5th term**

4. **What value should replace \( n \)**:
- To find \( a_5 \), replace \( n \) with 5 in the formula:
\[
n = 5
\]
- **Response**: **5**

To summarize the responses:
- Common Difference: **7**
- First Term: **8**
- \( a_5 \) represents: **5th term**
- Value to replace \( n \): **5**
Answered by GPT-4o mini
To find the 5th term \( a_5 \) using the explicit formula:

\[
a_n = -5 + 10(n - 1)
\]

Substituting \( n = 5 \):

\[
a_5 = -5 + 10(5 - 1)
\]
\[
= -5 + 10(4)
\]
\[
= -5 + 40
\]
\[
= 35
\]

So, the 5th term \( a_5 \) is **35**.

**Response**: **35**
Answered by GPT-4o mini
To find the correct recursive formula for the sequence \(2, 7, 12, 17, 22, 27\), we first identify the first term and the pattern in the sequence.

1. **First term**:
- The first term \(a_1 = 2\).

2. **Common difference**:
- The differences between consecutive terms are:
- \(7 - 2 = 5\)
- \(12 - 7 = 5\)
- \(17 - 12 = 5\)
- \(22 - 17 = 5\)
- \(27 - 22 = 5\)
- The common difference \(d = 5\).

Now, we can construct the recursive formula:

- The first term is \(a_1 = 2\).
- The recursive relationship based on the common difference is \(a_n = a_{n-1} + 5\).

Thus, the correct recursive formula is:
\[
a_1 = 2; \quad a_n = a_{n-1} + 5
\]

Now, let's compare this with the given options:

1. **a1 = 7; an = an−1 + 2** (Incorrect)
2. **a1 = 5; an = an−1 + 2** (Incorrect)
3. **a1 = 2; an = an−1 + 5** (Correct)
4. **a1 = 2; an = an−1 + 7** (Incorrect)

The correct response is:

**Response**: **a1 = 2; an = an−1 + 5**
Answered by GPT-4o mini
To find the appropriate function rule that represents the total number of miles \( M \) on the odometer after \( w \) weeks, we start with the initial mileage and add the amount of mileage added per week times the number of weeks.

1. **Initial mileage**: The car starts with 121,358 miles.
2. **Mileage accumulation**: The car accumulates 255 miles each week.

The function \( M(w) \) representing the total number of miles after \( w \) weeks can be expressed as:

\[
M(w) = \text{Initial mileage} + \text{(mileage per week)} \times \text{(number of weeks)}
\]

Putting this together, we have:

\[
M(w) = 121,358 + 255w
\]

Now, let's compare this with the provided options:

1. **M(w)=121,358w+255** (Incorrect)
2. **M(w)=121,358w+255w** (Incorrect)
3. **M(w)=121,358+255w** (Correct)
4. **M(w)=121,358+255** (Incorrect)

The correct response is:

**Response**: **M(w)=121,358+255w**

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