Write an equation for the exponential function represented in the graph below.

Step-by-step explanation:

we know that  

The exponential function is of the form

where

a is the initial value or y-intercept

b is the base or factor growth

r is the rate of change

In this problem we have

looking at the graph

Is a exponential growth function (as the value of x increases the value of y increases)

so

The y-intercept is the point (0,4)

so

substitute

From the graph take the point (1,8)

substitute in the exponential function and solve for b

therefore

The exponential function is equal to

x = 12

y = 1

for the points!