Answer:
[tex]f(n) = 26- 7n[/tex] --- (a)
[tex]f(n) = 5.7- 4.2n[/tex] ---- (b)
Step-by-step explanation:
Given
[tex]a_n = 19 - 7(n-1)[/tex]
[tex]a_n = 1.5 - 4.2(n-1)[/tex]
Required
Rewrite as a function
[tex]a_n = 19 - 7(n-1)[/tex]
Rewrite
[tex]f(n) = 19 - 7(n-1)[/tex]
Open bracket
[tex]f(n) = 19 - 7n+7[/tex]
Collect Like Terms
[tex]f(n) = 19 +7- 7n[/tex]
[tex]f(n) = 26- 7n[/tex]
[tex]a_n = 1.5 - 4.2(n-1)[/tex]
Rewrite
[tex]f(n) = 1.5 - 4.2(n-1)[/tex]
Open bracket
[tex]f(n) = 1.5 - 4.2n+4.2[/tex]
Collect Like Terms
[tex]f(n) = 1.5 +4.2- 4.2n[/tex]
[tex]f(n) = 5.7- 4.2n[/tex]
