We want to determine the domain of [tex]{y=3 \cdot 2^{-x}=3 \cdot ({2^{-1}})^x=3 \cdot ({ \frac{1}{2}})^x[/tex]
any function of the form [tex]y=f(x)=a \cdot b^x[/tex] is called an "exponential function",
the only condition is that b is positive and different from 1, and a is a nonzero real number.
The domain of such functions is all real numbers.
That is for any x, the expression 3(2^-x) "makes sense".
Answer: The domain is all real numbers
