Question

which exponential function has a growth factor of 1/2

Answer 1

An exponential function with a growth factor of 1/2 would have 1.5^x as part of it.$y=a(1+0.5)^{x}$
The exponential growth function is as follows.
$y=a(1+r)^{x}$
r is the rate of growth (0.50)