Step-by-step explanation:
Here 6 - 8 = 4 - 6 = 2 - 4 = 0 - 2 = - 2
Thus, the common difference between any two consecutive term is - 2.
The recursive formula is given as:
[tex]f(1)=a_1 = 8\\\\
f(2)=a_2 = a_1 - 2\\\\
f(3)=a_3 = a_2 - 2\\\\
f(4)=a_4 = a_3 - 2\\\\
f(5)=a_5 = a_4 - 2\\\\
\therefore f(n) = a_n=a_{n-1}-2 \\ [/tex]