Exponential Growth:

•       pattern of change that increases over time

•       Each value is multiplied by the previous value by a constant factor which is called the growth factor

•       How is this different from linear equations?

•       Exponential graphs start increasing slowly at first and then quickly

•       How is this different from linear graphs?

•       How is this different from quadratic graphs?

 

Growth Factor:

•       Constant factor greater than 1

•       You can find it by dividing each successive y-value by the previous y-value

•       1 plus the % increase as a rate (decimal)

•       Examples in real-life: investments, cell phone use, internet use, computers in the home, population growth

 

Exponential Growth Equations:    y = a(b)^x

       a = the starting amount; it also is the y-intercept

       b = the growth factor

   x = the time interval such as hours, days, years

How is this equation different from linear equations?                                                   

Exponential Decay:

•       pattern of change that decreases over time

•       each value is multiplied by the previous value by a constant factor which is called the decay factor;

•       You can find it by dividing each successive y-value by the previous y-value

•       How is this similar to exponential growth?

•       1 minus the % decrease as a rate (decimal) OR ask yourself what % is remaining?

•       How is this different from exponential growth?

•       y = a(b)^x same equation but the decay factor will be <1  Why?

•       The graph starts out decreasing slowly then decreases quickly

•       How is this different from exponential growth?

•       Will the graph ever go pass the x-intercept?

•       Examples in real-life: carbon dating to find the age of an object/organism;  decay of radioactive substances; populations of endangered species; turntable sales