Graphs

Writing a Function

Example 1

Write an exponential function WritingFunctionFromGraph for the graph below.

FuncGraphEx1-1

Step 1. Find the y-intercept

The y-intercept is identified on the graph as (0, 500).

Step 2. Substitute a point into the equation to find the common ratio

FuncGraphEx1-2

Step 3. Substitute the values of a and b into the equation.

y = 500 . FuncGraphEx1-3