Middle School

Represent the arithmetic series using the recursive formula.

Series: 94, 89, 84, 79, …

A. \( f(n) = f(1) + (-5) \)
B. \( f(n) = f(1) + 5 \)
C. \( f(n) = f(n - 1) + (-5) \)
D. \( f(n) = f(n - 1) + 5 \)

Answer :

Answer:

Option C) is correct

That is the given arithmetic sequence represents the recursive formula is f(n)=f(n-1)+(-5)

Step-by-step explanation:

The given arithmetic sequence is [tex]{\{94,89,84,79,...}\}[/tex]

Let f(1)=94,f(2)=89,f(3)=84,...

To find the common difference d :

[tex]d=f(2)-f(1)[/tex] ,

[tex]=89-94[/tex]

[tex]=-5[/tex]

Therefore d=-5

[tex]d=f(3)-f(2)[/tex] ,

[tex]=84-89[/tex]

[tex]=-5[/tex]

Therefore d=-5

Therefore the common difference d=-5

check the recursive formula [tex]f(n)=f(n-1)+d[/tex] which represents the given arithmetic sequence

Put n=2 and d=-5 in [tex]f(n)=f(n-1)+d[/tex] we get

[tex]f(2)=f(2-1)+(-5)[/tex]

[tex]=f(1)-5[/tex]

[tex]=94-5[/tex]

Therefore f(2)=89

Put n=3 and d=-5 in [tex]f(n)=f(n-1)+d[/tex] we get

[tex]f(3)=f(3-1)+(-5)[/tex]

[tex]=f(2)-5[/tex]

[tex]=89-5[/tex]

Therefore f(3)=84

and so on

Therefore the recursive formula [tex]f(n)=f(n-1)+d[/tex] where d=-5

Therefore the recursive formula [tex]f(n)=f(n-1)+(-5)[/tex] represents the given arithmetic sequence

Answer:

f(n) = f(n − 1) + (−5)

Step-by-step explanation:

The answer is C. I took the test and earned a 100%