Answer
B. f(n) = 56(0.5)^n-1
Explanation
f(n) (1) 56
(2) 28
(3) 14
(4) 7
To find the correct relation we have to test all of them.
A. f(n) = 28(0.5)^n
f(1) = 28(0.5)¹
= 28 × 0.5 = 14
f(n) = 28(0.5)^n ⇒ Not correct relation
B. f(n) = 56(0.5)^n-1
f(1) = 56(0.5)¹⁻¹ = 56×1
= 56
F(2) = 56(0.5)²⁻¹ = 56 × 0.5 = 28
F(3) = 56(0.5)³⁻¹ = 56 × 0.25 = 14
f(n) = 56(0.5)^n-1 ⇒ It is the correct relation
C. f(n) = 56(0.5)^n
f(1) = 56(0.5)¹ = 56 × 0.5 = 28
f(n) = 56(0.5)^n ⇒ Not correct relation
D. f(n) = 112(0.5)^n-1
f(1) = 112(0.5)¹⁻¹ = 112 × 1 = 112
f(n) = 112(0.5)^n-1 ⇒ Not correct relation
