Answer:
[tex]f(n) =4 + f(n-1) \\for\ n>2[/tex]
Step-by-step explanation:
Given
[tex]f(1)=2\\ f(2)= 6\\ f(3)= 10\\ f(4)= 14\\ f(5)= 18[/tex]
Required
Determine the formula
First, we need to solve common difference (d)
[tex]d = f(n) - f(n-1)[/tex]
Take n as 2
[tex]d = f(2) - f(2-1)[/tex]
[tex]d = 6 - 2[/tex]
[tex]d = 4[/tex]
Represent each function as a sum of the previous
[tex]f(1) = 2[/tex]
[tex]f(2) = 2 + 4 = f(1) + 4[/tex]
[tex]f(3) = 6 + 4 = f(2) + 4[/tex]
[tex]f(4) = 10 + 4 = f(3) + 4[/tex]
[tex]f(5) = 14 + 4 = f(4) + 4[/tex]
Represent the function as [tex]f(n)[/tex]
[tex]f(n) =f(n-1) + 4[/tex]
Reorder
[tex]f(n) =4 + f(n-1) \\for\ n>2[/tex]