11 * 11 = 4

12 * 12 = 9

13 * 13 = 16

14 * 14 = ??

Answer It

Describe the transformations that would be made to y = 3x

Describe the transformations that would be made to y = 3x

51. 2(3) 1xy 1

2. (3) 43

xy

Is this a growth or decay model?Is this a growth or decay model?

The swans on Elsworth Pond have been increasing in number each year. Felix has beenkeeping track and so far he has counted 2, 4, 7, 17, and 33 swans each year for the past fiveyears.

The swans on Elsworth Pond have been increasing in number each year. Felix has beenkeeping track and so far he has counted 2, 4, 7, 17, and 33 swans each year for the past fiveyears.1) Make a scatter plot of the data.

2) Is this a linear or exponential model?

3) How many swans should Felix expect next year?

1) Make a scatter plot of the data.

2) Is this a linear or exponential model?

3) How many swans should Felix expect next year?

P87MCC9-12.F.LE.5 Interpret the parameters in a linear or exponential function in terms of a context.

CC Coordinate AlgebraDay 42 (3-11-13)

UNIT QUESTION: How can we use real-world situations to construct and compare linear and exponential models and solve problems?Standard: MCC9-12.A.REI.10, 11, F.IF.1-7, 9, F.BF.1-3, F.LE.1-3, 5

Today’s Question:How is interest earned in the bank modeled with an exponential equation?Standard: MMCC9-12.F.LE.1

1t

y P r

y = balance

P = initial

t = time in years

r = % of increase

1+r = growth factor

y = balance

P = initial

t = time in years

r = % of increase

1+r = growth factor

1t

y P r

y = balance

P = initial

t = time in years

r = % of decrease

1- r = decay factor

y = balance

P = initial

t = time in years

r = % of decrease

1- r = decay factor

In 2000, the cost of tuition at a state university was $4300. During the next 8 years, the tuition rose 4% each year.

A) Write a model the gives the tuition y (in dollars) t years after 2000.

B) What is the growth factor?

C) How much would it cost to attend college in 2010? In 2015?

D) How long it will take for tuition to reach $9000?

A 2010 Honda Accord depreciates at a rate of 11% per year. The car was bought for $25000.

A) Write a model the gives the value of the car y (in dollars) t years after 2010.

B) What is the decay factor?

C) How much is the car worth now? In 2015?

D) How long will it take for my car to be worth half?

Extension

A) What “r” value would be used if the principal is being doubled every year?

A) What about if it is tripled ever year?

Suppose you start work at $600 a week. After a year, you are given two choices for getting a raise:

a)2% a yearb)a flat $15 a week raise for each successive year.

Which option is better?

Which function has the greatest rate of change?

Option A

An investment of $1,000 earns interest at a rate of 3.75%, compounded monthly.

Option B

1t

y P r 1t

y P r

Practice Worksheet

1t

y P r 1t

y P r

Practice Worksheet