Understand what the letters and symbols in an exponential equation mean. In a typical exponential function equation, a small (a) signifies the original amount of an object before the day or growth is determined. A small (r) symbolizes the growth or decay rate of the object and is often displayed as a percentage. A small (x) reveals the time interval amounts that are recorded when determining the growth or decay of said object.
Build a chart with your information to begin tracking the possible decay or growth over time. Indicate the amount of time your data takes place during by using an (x.) One week or one month becomes x=1. The chart will indicate how many total weeks, months or years by using a separate block for each time frame. Under each week, month or year record the number amount of your object. Your chart might show that in 2008, 1000 people purchased a new television. In 2009, 800 people bought new televisions and in 2010, 750 people purchased a new television.
Write out your exponential function equation based on your chart information. When you write it out you are trying to find the answer to a question. The letter (y) represents the final number you are looking for. Your equation will show that y = a (1+r) x. When you take (a) and multiply it by (r) the rate of either decay or growth and multiply that by the amount of time you get the answer, or (y.)
Make a scatter plot graph using a graphing calculator. Plot your data points into your graphing calculator and then employ the Y1 to equal the function and proceed to graph. Properly entered, this creates a scatter plot that will "overlap" the function and give you a visual "map" of your results.