1. Warm Up 1) Change from percent to decimal 56% 2) Tom had four flowers patch. The flowers grew exponentially, doubling every 8 hours. 1) Write the equation to model this situation. 2) How many flowers would Tom have after 2 days?

3. Exponential Functions Remember! An exponential function is a function with the general form y = ab x a ≠ 0 and b > 0, and b ≠ 1

4. A and B A Starting Value B is direction GrowthDecay b > 10 < b < 1

5. Y-Intercept and Growth vs. Decay Y-intercept and Growth vs. Decay Identify each y-intercept and whether it is a growth or decay 1. Y= 3(1/4) x 2. Y=.5(3) x 3. Y = (.85) x 4. Y = 300(1.3) x 5. Y = 4500(.4) x 6. Y = 76(3/4) x

6. Increase and Decrease by percent Exponential Models can also be used to show an increase or decrease by a percentage.

7. Increase and Decrease by percent The rate of increase or decrease is a percent, we use a change factor/base of 1 + r or 1 – r. GrowthDecay. b > 10 < b < 1 Change factorChange Factor (1 + r) (1 - r)

8. Percent to Change Factor When something grows or decays by a percent, we have to add or subtract it from one to find b. 1. Increase of 25%2. increase of 130% 2. Decrease of 30% 4. Decrease of 80%

9. Growth Factor to Percent Find the percent increase or decease from the following exponential equations. 1. Y = 3(.5) x 2. Y = 2(2.3) x 3. Y = 0.5(1.25) x

10. Percent Increase and Decrease A dish has 212 bacteria in it. The population of bacteria will grow by 80% every day. How many bacteria will be present in 4 days?

11. Percent Increase and Decrease The house down the street has termites in the porch. The exterminator estimated that there are about 800,000 termites eating at the porch. He said that the treatment he put on the wood would kill 40% of the termites every day. How many termites will be eating at the porch in 3 days?