Find the recursive formula for the geometric sequence. Then find a5.
2, 14, 98, 686, ...
Question 12 options:

A)

an = an – 1 ⋅ 7; 693

B)

an = an – 1 ⋅ 7; 33,614

C)

an = an – 1 ⋅ 7; 98

D)

an = an – 1 ⋅ 7; 4,802



Answer :

Xaioo

Answer:

[tex][/tex] The recursive formula for a geometric sequence is:

a_n = a_n-1 [tex] \times[/tex] r

where:

• a_n is the nth term in the sequence

• a_n-1 is the (n-1)th term in the sequence

• r is the common ratio between each term

To find the common ratio, we can divide any term by the previous term. For example:

r = [tex]\frac{a_2}{a_1}[/tex] = [tex]\frac{14}{2}[/tex] = 7

Therefore, the recursive formula for the given sequence is:

a_n = a_n-1 [tex] \times[/tex] 7

To find a_5, we can substitute n = 5 into the recursive formula and evaluate it:

```

a_5 = a_4 [tex] \times[/tex] 7

a_4 = a_3 [tex] \times[/tex] 7

a_3 = a_2 [tex] \times[/tex] 7

a_2 = a_1 [tex] \times[/tex] 7

```

Substituting these equations into each other, we get:

a_5 = a_1 [tex] \times[/tex] 7⁵

Since the first term in the sequence is 2, we have:

a_5 = 2 [tex] \times[/tex] 7⁵ = 33,614

Therefore, the answer is B) a_n = a_n-1 [tex] \times[/tex] 7; 33,614.

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