Answer:

Step-by-step explanation:
The value of the function doubles with every increment of 1 in the value of x. Since the value is being doubled every time, i.e. multiplied by 2, it gives us a hint that the given function would be an exponential function. Because in exponential function there is a constant multiplicative growth.
A general parent exponential function is of the form:

In order to find the parent function, we need to find the value of a. The growth factor of the exponential function is determined by the value of a. For example, for a = 3, every value will be 3 times the previous value.
Since, in this case every value is twice the previous value, so the value of a would be 2.
Therefore, the parent function would be:

Check:
For x = 0, f(x) = 1
For x = 1, f(x) = 2
For x = 2, f(x) = 4 and so on
We can observe that function doubles for each increase of 1 in the value of x.