Answer:

Explanation:
Equation for an exponential function is given as following: 

Where b is the common ratio and 
c is the horizontal asymptote (y value) 
a is the coefficient of exponential term of 

 are the points on the function.
Here, we are given that:
Common ratio, b = 2
Horizontal asymptote at y, c = 4
So, the equation becomes (let us put the values of b and c):

We need the value of a. Let us put value of (x,y) as (2,10).

So, the final equation of the exponential function is:
