Use the explicit formula an=4−3n

to find the seventh term of the arithmetic sequence.(1 point)
Responses

a7=−17
a subscript 7 baseline equals negative 17

a7=−1
a subscript 7 baseline equals negative 1

a7=1
a subscript 7 baseline equals 1

a7=7

9 answers

To find the seventh term of the sequence given by the explicit formula \( a_n = 4 - 3n \), we need to substitute \( n = 7 \) into the formula.

\[ a_7 = 4 - 3(7) \] \[ a_7 = 4 - 21 \] \[ a_7 = -17 \]

So the seventh term \( a_7 \) is \(-17\).

The correct answer is: a7=−17

Given the recursive formula for the geometric sequence a1=5
, an=2/5an−1
, find the second term of the sequence.(1 point)
Responses

a2=5 2/5
a subscript 2 baseline equals 5 Start Fraction 2 over 5 End Fraction

a2=8/5
a subscript 2 baseline equals Start Fraction 8 over 5 End Fraction

a2=2/5
a subscript 2 baseline equals Start Fraction 2 over 5 End Fraction

a2=2

To find the second term of the geometric sequence given the recursive formula \( a_1 = 5 \) and \( a_n = \frac{2}{5} a_{n-1} \), we will calculate \( a_2 \) using the formula.

Since we know the first term is \( a_1 = 5 \), we can use it to find \( a_2 \):

\[ a_2 = \frac{2}{5} a_1 = \frac{2}{5} \times 5 \] \[ a_2 = 2 \]

Thus, the second term \( a_2 \) is \( 2 \).

The correct answer is: a2=2

Use the recursively defined geometric sequence a1=5/6
, an=4an−1
and find the common ratio.(1 point)
Responses

−2/3
negative Start Fraction 2 over 3 End Fraction

10/3
Start Fraction 10 over 3 End Fraction

4
4

5/6

In a geometric sequence, the common ratio \( r \) is the factor by which each term is multiplied to get the next term. Given the recursive formula for the geometric sequence:

  • \( a_1 = \frac{5}{6} \)
  • \( a_n = 4 a_{n-1} \)

The common ratio can be identified from the formula, where \( a_n \) is determined by multiplying the previous term \( a_{n-1} \) by 4.

Therefore, the common ratio \( r \) is:

\[ r = 4 \]

The correct answer is: 4

Find the recursive formula for the arithmetic sequence 7, 5, 3, 1, −1
, . . .(1 point)
Responses

a1=7
, an=2an−1
a subscript 1 baseline equals 7 , a subscript n baseline equals 2 a subscript n minus 1 baseline

a1=7
, an=an−1−2
a subscript 1 baseline equals 7 , a subscript n baseline equals a subscript n minus 1 baseline minus 2

a1=7
, an=an−1+2
a subscript 1 baseline equals 7 , a subscript n baseline equals a subscript n minus 1 baseline plus 2

a1=7
, an=−2an−1

To find the recursive formula for the arithmetic sequence \( 7, 5, 3, 1, -1, \ldots \), we first identify the first term and the common difference.

  1. First Term: \( a_1 = 7 \)
  2. Common Difference: The difference between consecutive terms is:
    • \( 5 - 7 = -2 \)
    • \( 3 - 5 = -2 \)
    • \( 1 - 3 = -2 \)
    • \( -1 - 1 = -2 \)

Thus, the common difference \( d \) is \( -2 \).

The recursive formula for an arithmetic sequence is given by:

\[ a_n = a_{n-1} + d \]

For our sequence, it becomes:

\[ a_n = a_{n-1} - 2 \]

So, the complete recursive formula for this sequence is:

\[ a_1 = 7, \quad a_n = a_{n-1} - 2 \]

The correct answer is: a1=7, an=an−1−2

Which of the following correctly uses the explicit formula, An=1/4+(n−1)⋅12
, to find the 9th term of the described arithmetic sequence?(1 point)
Responses

414
4 Start Fraction 1 over 4 End Fraction

834
8 Start Fraction 3 over 4 End Fraction

814
8 Start Fraction 1 over 4 End Fraction

434

To find the 9th term of the arithmetic sequence described by the explicit formula

\[ A_n = \frac{1}{4} + (n - 1) \cdot 12, \]

we need to substitute \( n = 9 \) into the formula.

\[ A_9 = \frac{1}{4} + (9 - 1) \cdot 12 \] \[ A_9 = \frac{1}{4} + 8 \cdot 12 \] \[ A_9 = \frac{1}{4} + 96 \]

Now, we can convert \( 96 \) to a fraction with a common denominator of 4 to combine the terms:

\[ 96 = \frac{96 \cdot 4}{4} = \frac{384}{4}, \]

So,

\[ A_9 = \frac{1}{4} + \frac{384}{4} = \frac{1 + 384}{4} = \frac{385}{4}. \]

Now, let's convert \(\frac{385}{4}\) back to a mixed number if useful:

\[\frac{385}{4} = 96.25 = 96\frac{1}{4}.\]

Let's check the available responses for \( \frac{385}{4} \):

  1. \( 4 \frac{1}{4} \) (which is 4.25)
  2. \( 8 \frac{3}{4} \) (which is 8.75)
  3. \( 8 \frac{1}{4} \) (which is 8.25)
  4. \( 4 \cdot 34 \) (which is 34)

It appears there has been an error in interpreting the choices or in the calculations. On just confirming our computed term:

\[ A_9 = \frac{385}{4}. \]

This value suggests \( 96\frac{1}{4} \) which is not listed; rather \( \frac{381}{4} \) or any fraction close to mixed from available choices may have been misplaced.

Please restate the responses provided. Are any corrections filed on the selections?