3-28 Exponential Growth and Decay, Half-Life, and Compound .notebookMarch 28, 2014

Math Origami

Take a sheet a paper that is .001 cm thick.

How many times can you fold the piece of paper? 3-28 Exponential Growth and Decay, Half-Life, and .notebookMarch 28, 2014

How thick is the paper after....

1 fold? 2 folds? 3 folds?

http://www.youtube.com/watch?v=AmFMJC45f1Q 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Increasing exponentially means that the number is constantly multiplying by itself.

Exponential growth can be modeled with the function

OR 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Ex. 1) Identify the initial amount a and the growth factor b in each . a.)

b.) 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Ex. 2) Since 1985, the daily cost of patient care in community hospitals in the US about 8.1% per year. In 1985, such hospital costs were an average of $480 per day.

a.) Write an equation to model the cost of hospital care.

b.) Use your equation to find the approximate cost per day in 2000? 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Decreasing exponentially means that the number is constantly dividing by itself. Exponential decay can be modeled by the function 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Ex. 3) Since 1980, the number of gallons of whole milk each person in the US drinks each year has decreased 4.1% each year. In 1980, each person drank an average of 16.5 hallons of whole milk per year.

a.) Write an equation to model the gallons of whole milk drunk by one person.

b.) Use your equation to find the approximate consumption per person of whole milk in 2000. 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Compound Interest When the bank pays interest on both the initial amount and the interest the account has already earned. 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Ex. 3) Suppose your parents deposited $1500 in an account paying 6.5% interest compounded annually when you were born. Find the account balance after 18 years. 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Ex. 4) Find the balance in the account.

$4000 principal earning, 6% compounded annually, after 5 years 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Half-Life Over x (days, months, years, etc.) the amount of substance is divided in half.

Ex. 5) The half-life of iodine-124 is 4 days. A technician measures a 40-mCi sample of iodine-124.

a.) How many half-lives of iodine-124 occur in 16 days?

b.) How much iodine-124 is in the sample 16 days after the technician measures the original sample? 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014

Homework Page 441 Exercises 1-8,12-18 3-28 Exponential Growth and Decay, Half-Life, and Compound Interest.notebookMarch 28, 2014