Question

Select the sequence that matches the recursive formula. a1 = 39 1n = an-1 -5.

Answer 1

Answer:

Option 2nd is correct

39, 34, 29, 24,....

Step-by-step explanation:

Given the recursive formula:

$a_1 = 39$

$a_n = a_{n-1}-5$

For n = 2

$a_2 = a_{2-1}-5$

⇒$a_2 = a_{1}-5=39-5 = 34$

⇒$a_2 = 34$

For n= 3:

$a_3 = a_{3-1}-5$

⇒$a_3= a_{2}-5=34-5 = 29$

⇒$a_3= 29$

For n = 4:

$a_4 = a_{4-1}-5$

⇒$a_4= a_{3}-5=29-5 = 24$

⇒$a_4= 24$ and so on....

We get the sequence:

39, 34, 29, 24,....

Therefore, the sequence that matches the recursive formula is, 39, 34, 29, 24,....

Answer 2

From what you wrote I can assume thad difference of sequence is equal to -5.
The only matching sequence for that recursive formula is the second one:
..., 34, 29, 24, ...