Exponential Functions
Exponential functions are typically organized in this format:

To find the equation given the graph of an exponential function:
- Identify the horizontal asymptote
 ⇒ asymptote - a line towards which a graph appears to travel but never meets
 ⇒ If the horizontal asymptote is not equal to 0, we add this at the end of the function equation.
- Identify the y-intercept
 ⇒ This is our a value.
- Identify a point on the graph and solve for c
Solving the Question
Identify the horizontal asymptote
In this question, it appears to be x = 0. 
Identify the y-intercept
The y-intercept is the value of y at which the graph appears to cross the y-axis. In this graph, it appears to be 100. This is our a value. Plug this into 
 :
:

Solve for c
We can use any point that falls on the graph for this step. For instance, (1,50) appears to be a valid point. Plug this into our equation and solve for c:

Plug c back into our original equation:

Answer
