Given
the population of native birds in first year is 14,000
Decreasing rate = 10%
Find
f(1)
f(n)=f(n-1).--
population after 4 years
Explanation
given after 1 year , the population is 14,000
so , f(1) = 14,000
the population is decreasing 10 %
so , population decay =
[tex]\begin{gathered} f(n)=f(n-1)(1-r)^n \\ f(n)=f(n-1)(1-0.1)^1 \\ f(n)=f(n-1)(0.9) \end{gathered}[/tex]
f(2) =
[tex]\begin{gathered} f(1)(0.9) \\ 14000(0.9) \\ 12600 \end{gathered}[/tex]
f(3) =
[tex]\begin{gathered} f(3)=f(2)0.9 \\ f(3)=12600(0.9) \\ f(3)=11340 \end{gathered}[/tex]
After 4 years ,
f(4) =
[tex]\begin{gathered} f(4)=f(3)0.9 \\ f(4)=11340(0.9) \\ f(4)=10206 \end{gathered}[/tex]
Final Answer
Therefore ,
f(1) = 14000
f(n)=f(n-1),(0.9)
After 4 years , 10206 birds will remain