Monday 3/22/10: Fractional Growth Factors

Today in class, we went over the Exploring Exponential Functions worksheet we started on Friday. We determined the effect of a, b, and c of the graph of the equation y=a(b^x)+c:

• a is the starting point of the equation. It is the original y-intercept. When a is a negative number,the line of the equation points downward. On the other hand, when a is a positive number, the resulting line points up, giving it a shape similar to an U.


• b is the growth rate of the equation. It defines the steepness of the graph.


• c shifts the curved line up or down on the y-axis. When added to the a value of the equation, it results in the final y-intercept of the graph.

We were introduced to fractional growth factors today. We saw that whether the growth factor was fractional or not did not effect the form of the equation. We did a problem in class about rabbits. We were given a table of the growth of a particular rabbit population. Using the information, we found that the growth rate was about 1.8. This did not influence the appication of y=a(b^x) to its graph.