Graphs
Graphs
Writing a Function
Example 2
Write an exponential function for a graph that includes the points (2, 2) and (3, 4). 
Step 1. Substitute the values of each point into the function 
. 
1.) 2 = a.b2 2.) 4 = a.b3
Step 2. Solve for "a" using the first function

Step 3. Substitute the value of "a" from step 2 into the second function. And solve for "b".
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Step 4. Substitute "b" back into the first function and solve for "a" .

Step 5. Substitute the values of "a" and "b" into the original function 
.
y = 
. 2 x