⎧

f(1)=−8

f(n)=f(n−1)−3



Find an explicit formula for f(n)f(n)f, left parenthesis, n, right parenthesis

f(n)=-5-3n

Step-by-step explanation:

Given the recursive formula of a sequence

f(1)=−8

f(n)=f(n−1)−3

We are to determine an explicit formula for the sequence.

f(2)=f(2-1)-3

=f(1)-3

=-8-3

f(2)=-11

f(3)=f(3-1)-3

=f(2)-3

=-11-3

f(3)=-14

We write the first few terms of the sequence.

-8, -11, -14, ...

This is an arithmetic sequence where the:

First term, a= -8

Common difference, d=-11-(-8)=-11+8

d=-3

The nth term of an arithmetic sequence is determined using the formula:

T(n)=a+(n-1)d

Substituting the derived values, we have:

T(n)=-8-3(n-1)

=-8-3n+3

T(n)=-5-3n

Therefore, the explicit formula for f(n) can be written as:

f(n)=-5-3n

5th grade mean: 4.67

7th grade mean: 3.46

5th grade median: 5

7th grade median: 3.5

Step-by-step explanation:

I did the math :) (also sorry if this is late, I was looking for the answer but no one had it, so I decided to help out other peeps with the same problem)