Jika f(1) = 5 dan f(x+1) = 2f(x),maka f(6) =

Misal, x = 1

f(1 + 1) = 2f(1)
f(2) = 2(5)
f(2) = 10

misal, x = 2

f(2 + 1) = 2f(2)
f(3) = 2(10)
f(3) = 20

misal, x = 3

f(3 + 1) = 2f(3)
f(4) = 2(20)
f(4) = 40

terlihat pola geometri,

f(1) = 5
f(2) = 10
f(3) = 20
f(4) = 40
f(5) = 80
f(6) = 160