Question

Which graph is the sequence defined by the function f(x) = 3(2)x-1?

On a coordinate plane, 5 points are plotted. The points are (0, 2), (1, 6), (2, 18), (3, 54), (4, 162).
On a coordinate plane, 5 points are plotted. The points are (1, 2), (2, 6), (3, 18), (4, 54), (5, 162).
On a coordinate plane, 6 points are plotted. The points are (0, 3), (1, 6), (2, 12), (3, 24), (4, 48), (5, 96).
On a coordinate plane, 5 points are plotted. The points are (1, 3), (2, 6), (3, 12), (4, 24), (5, 48).

Answer 1

Assuming f(x) = 3·2^(x−1), evaluate at integer x:

x=1: 3·2^0 = 3 → (1,3)
x=2: 3·2^1 = 6 → (2,6)
x=3: 12 → (3,12)
x=4: 24 → (4,24)
x=5: 48 → (5,48)

So the correct graph is the fourth one: (1,3), (2,6), (3,12), (4,24), (5,48).