Do Now Grab a calculator If you had

Do Now: • Grab a calculator • If you had to finish your lab for HW, put it in my basket • On the HW for 7. 6 side, the b value should be 1. 055…also #5 you needed a calculator…. Do/Fix those problems NOW!! • After you fix them, complete the back of the Do Now worksheet from yesterday (about a diver) ▫ If absent yesterday, grab the worksheet off my podium

Exponential Growth & Decay

Standard Form: • y = a • bx • However, depending on the question, we have to change the growth factor.

• The number of students enrolled at a college is 15, 000 and grows 4% each year. After 25 years, what can we predict the number of students enrolled in college will be? • Usually we would write it like this: y = 15, 000(. 04)25 y = 1. 689 x 10 -31 (that’s a really small number) However, the number of students enrolled is suppose to grow…dose this answer make sense?

Exponential Growth: • • A = the balance P = principle (initial/starting amount) r = the annual interest rate (decimal) t = the time

• The number of students enrolled at a college is 15, 000 and grows 4% each year. After 25 years, what can we predict the number of students enrolled in college will be? • Now with the new formula we write it like this: A = 15, 000(1+. 04)25 A = 15, 000(1. 04) 25 A= 39, 987 students enrolled Does this answer make sense? YES!

With Exponential Growth, we also have Exponential Decay

Exponential Decay: • • A = the balance P = principle (initial/starting amount) r = the annual interest rate (decimal) t = the time What is the difference between growth and decay? ?

Exponential Decay • You buy a new computer for college costing $2100. The computer decreases by 30% annually. What will the price of the computer be after four years of college?

How to know when to use which formula… What are some key words we can look for within word problems to decide? Exponential Growth • Growing • Increasing • Appreciates Exponential Decay • Decreases • Depreciates • Goes down

By looking at an equation, how can we tell if the function is exponential growth and exponential decay? • A = P( )t We look here rate > 1…. . growth rate < 1…. . decay

Growth or Decay? • A = 16(1. 025)5 • A = 180(. 04)20 • A = 45(. 45)15 • A = 10(1. 84)7 x • A = 2500(. 005)x • A = 50(2. 055)16

Growth & Decay Scavenger Hunt Complete the worksheet. You will find the answers around the room. Find the answer and write the letter in the spaces, check it with Ms. Taylor and she will give you the HW.