# How do you determine the formula for the graph of an exponential function given (0,2) and (3,1)?

##### 1 Answer

Sep 25, 2016

I found:

#### Explanation:

Let us start with the general form of an exponential function:

where

We use the coordinates of the points into the general expression to find the two constants:

**First** :

or:

so that

**Second** :

we know from the previous step that

and so:

take the natural log of both sides:

rearranging:

and:

Finally our function will be:

Graphically:

graph{2e^(-0.231x) [-10, 10, -5, 5]}