Barry has been watching the geese that live in his neighborhood. The number of geese changes each week.

n f(n)
1 56
2 28
3 14
4 7

Which function best shows the relationship between n and f(n)?

A.f(n) = 28(0.5)^n
B.f(n) = 56(0.5)^n - 1
C.f(n) = 56(0.5)^n
D.f(n) = 112(0.5)^n - 1

Respuesta :

The correct answer is:
B.

Explanation:
In order to find the appropriate equation for this example, we need to find one that works for the first point (1, 56).
This means when we put 1 in for n in the equation, we need to get 56 as an answer.
If you place 1 in for n in each of the equations, only B gives you 56.
f(n) = 56(0.5)
ⁿ⁻¹,
f(n) = 56(0.5)
,
f(n) = 56(1),
f(n) = 56.