Question 1 A)Use the explicit formula an=4−3nan=4−3n to find the seventh term of the arithmetic sequence.(1 point) Responses a7=1a7=1 a subscript 7 baseline equals 1 a7=7a7=7 a subscript 7 baseline equals 7 a7=−17a7=−17 a subscript 7 baseline equals negative 17 a7=−1a7=−1 a subscript 7 baseline equals negative 1 Question 2 A)Given the recursive formula for the geometric sequence a1=5a1=5, an=25an−1an=25an−1, find the second term of the sequence.(1 point) Responses a2=2a2=2 a subscript 2 baseline equals 2 a2=525a2=525 a subscript 2 baseline equals 5 Start Fraction 2 over 5 End Fraction a2=25a2=25 a subscript 2 baseline equals Start Fraction 2 over 5 End Fraction a2=85a2=85 a subscript 2 baseline equals Start Fraction 8 over 5 End Fraction Question 3 A)Use the recursively defined geometric sequence a1=56a1=56, an=4an−1an=4an−1 and find the common ratio.(1 point) Responses 4 4 5656 Start Fraction 5 over 6 End Fraction −23−23 negative Start Fraction 2 over 3 End Fraction 103103 Start Fraction 10 over 3 End Fraction Question 4 A)Find the recursive formula for the arithmetic sequence 7, 5, 3, 1, −1−1, . . .(1 point) Responses a1=7a1=7, an=−2an−1an=−2an−1 a subscript 1 baseline equals 7 , a subscript n baseline equals negative 2 a subscript n minus 1 baseline a1=7a1=7, an=an−1−2an=an−1−2 a subscript 1 baseline equals 7 , a subscript n baseline equals a subscript n minus 1 baseline minus 2 a1=7a1=7, an=2an−1an=2an−1 a subscript 1 baseline equals 7 , a subscript n baseline equals 2 a subscript n minus 1 baseline a1=7a1=7, an=an−1+2an=an−1+2 a subscript 1 baseline equals 7 , a subscript n baseline equals a subscript n minus 1 baseline plus 2 Question 5 A)Which of the following correctly uses the explicit formula, An=14+(n−1)⋅12An=14+(n−1)⋅12, to find the 9th term of the described arithmetic sequence?(1 point) Responses 434434 4 Start Fraction 3 over 4 End Fraction 414414 4 Start Fraction 1 over 4 End Fraction 814814 8 Start Fraction 1 over 4 End Fraction 834834 8 Start Fraction 3 over 4 End Fraction

5 answers

Let's solve each question step by step.

Question 1:

Given: \( a_n = 4 - 3n \)

To find the 7th term, we calculate \( a_7 \): \[ a_7 = 4 - 3(7) = 4 - 21 = -17 \] Answer: \( a_7 = -17 \)

Question 2:

Given: \( a_1 = 5 \) and \( a_n = 25a_{n-1} \)

To find the second term \( a_2 \): \[ a_2 = 25a_1 = 25 \times 5 = 125 \] Answer: \( a_2 = 125 \)

Question 3:

Given: \( a_1 = 56 \) and \( a_n = 4a_{n-1} \)

Here, the common ratio \( r \) is simply the multiplier we use to go from one term to the next: \[ r = 4 \] Answer: \( r = 4 \)

Question 4:

The sequence is: 7, 5, 3, 1, -1...

To determine the recursive formula, we notice that the difference between consecutive terms is -2:

  • From 7 to 5: \(-2\)
  • From 5 to 3: \(-2\)
  • From 3 to 1: \(-2\)
  • From 1 to -1: \(-2\)

Thus, the recursive formula is: \[ a_1 = 7, \quad a_n = a_{n-1} - 2 \] Answer: \( a_1 = 7, a_n = a_{n-1} - 2 \)

Question 5:

Given: \( A_n = 14 + (n - 1) \cdot 12 \)

To find the 9th term: \[ A_9 = 14 + (9 - 1) \cdot 12 = 14 + (8) \cdot 12 = 14 + 96 = 110 \] Answer: \( A_9 = 110 \)

As a recap the answers to each respective question are:

  1. \( a_7 = -17 \)
  2. \( a_2 = 125 \)
  3. Common ratio \( r = 4 \)
  4. \( a_1 = 7, a_n = a_{n-1} - 2 \)
  5. \( A_9 = 110 \)
5 question: explicit formula, An= 1/4 + (n-1) * 1/2
2 question: a1=5, an=2/5an-1

Thank you for the clarification. Let's solve the specified questions using the provided formulas.

Question 5 (Explicit Formula):

Given: \( A_n = \frac{1}{4} + (n - 1) \cdot \frac{1}{2} \)

To find the 9th term \( A_9 \): \[ A_9 = \frac{1}{4} + (9 - 1) \cdot \frac{1}{2} \]

Calculating it step by step: \[ A_9 = \frac{1}{4} + 8 \cdot \frac{1}{2} \] \[ A_9 = \frac{1}{4} + 4 \] Converting 4 to fractional form: \[ A_9 = \frac{1}{4} + \frac{16}{4} = \frac{1 + 16}{4} = \frac{17}{4} \]

Thus, the answer for Question 5 is: Answer: \( A_9 = \frac{17}{4} \)


Question 2 (Recursive Formula):

Given: \( a_1 = 5 \) and \( a_n = \frac{2}{5} a_{n-1} \)

To find the second term \( a_2 \): \[ a_2 = \frac{2}{5} a_1 = \frac{2}{5} \cdot 5 = 2 \]

Thus, the answer for Question 2 is: Answer: \( a_2 = 2 \)


Summary of Answers:

  1. Question 5: \( A_9 = \frac{17}{4} \)
  2. Question 2: \( a_2 = 2 \)

If you have any more questions or need further clarification, feel free to ask!

question 5 responses are
4 3/4
4 1/4
8 1/4
8 3/4

Thank you for providing the response options for Question 5. Let's correctly determine the 9th term using the explicit formula given and match it with the provided choices.

Question 5:

Given explicit formula: \[ A_n = \frac{1}{4} + (n - 1) \cdot \frac{1}{2} \]

To find the 9th term \( A_9 \): \[ A_9 = \frac{1}{4} + (9 - 1) \cdot \frac{1}{2} \] \[ = \frac{1}{4} + 8 \cdot \frac{1}{2} \] \[ = \frac{1}{4} + 4 \] Convert 4 into fourths for easier addition: \[ 4 = \frac{16}{4} \] So, \[ A_9 = \frac{1}{4} + \frac{16}{4} = \frac{17}{4} \]

Now, let's convert \(\frac{17}{4}\) into a mixed number to compare: \[ \frac{17}{4} = 4 \frac{1}{4} \]

Thus, among the response options, the correct term is: Answer: \( 4 \frac{1}{4} \)

Thank you for your patience! Let me know if you need any further assistance.