Question

Write an exponential function for the set of points.
x 0 1 2 3 4
f(x) 27 9 3 1 1/3
A. f(x)=(1/3)^x
B. f(x)=3^x
C. f(x)=27(1/3)^x
D. f(x)=27(3)^x
Does this represent exponential growth or decay?
A. growth
B. decay

Answer 1

f(x) = 27(1/3)^x (choice C).
This is exponential decay (choice B) because each step multiplies by 1/3 (<1).