Answer to Question #57171 in Calculus for Box Cars

Question

Which functions in the table below give values that could not come from exponential functions?

x -3 -2 -2 0 1 2 3
f(x) 0.67 1.11 1.82 3 4.95 8.15 13.45
g(x) 0.125 0.25 0.5 1 2 4 8
h(x) 0.25 0.5 0.75 1 1.25 1.5 1.75
k(x) 64 16 4 0 0.25 0.0625 0.0156