 Def: Exponential Function  can be written as the equation.  When b>1, we have exponential growth.  When b< 1, we have exponential decay.  a = original amount  b = growth factor (usually a %)

 To find the “b” value for our function, use the formula b = 1+ r.  Percent Change =

 Write an exponential function for a graph that passes through the points (2, 2) & (3, 4).  Write an exponential function for a graph that passes through the points (2, 4) & (3, 16).  Write an exponential function for a graph that passes through the points (1, 6) & (0, 2)

 In a basketball tournament, the following table shows how many teams were left in a tournament after a certain number of weeks.  1) Graph the data  2) Find an exponential function that models this.  3) How many teams were left during the 3.4 week period? Weeks# of Teams Left

 Jim bought a new car for $20,000. After owning it for 1 year, its value depreciated down to $17,000.  1) Find an exponential function that models this data.  2) Find how much the car is worth 6 years after he bought it.

 Which car is worth more in 10 years? ◦ CAR A – bought for $30,000 and after 1 year, it depreciates to $20,000 ◦ CAR B – bought for $15,000 and after 2 years, it depreciates to $10,000

 An industrial machine has a decay factor of 0.75 per year. After 6 years, the machine is worth $7500. How much was it worth when they first bought it?  A house has a decay factor of 8/9. After 20 years of paying a mortgage, the house is worth $120,000. How much did the owners pay for the house?

 An initial population of 432 deer increases at an annual rate of 34%. Which exponential function models this data?  A)B)  C)D)