Transcript y=P(1+r)t Give the value of “r” and the growth or decay factor for each. 1.

y=P(1+r)t Give the value of “r” and
the growth or decay factor for each.
1. y=P(1.12)t
3. y=P(2)t
2. y=P(.77)t
4. y=P(.12)t
5. a population triples every year
P75
MCC9-12.F.LE.1 Distinguish
between situations that
can be modeled with
linear functions and with
exponential functions.
CC Coordinate Algebra
Day 43 (3-12-13)
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
y  P 1  r 
t
y  P 1  r 
y = balance
y = balance
P = initial
P = initial
t = time in years
t = time in years
r = % of increase
r = % of decrease
1+r = growth factor
1- r = decay factor
t
An antique car appreciates at a rate of 2.9% per
year. The car was bought for $25,000.
A) Write a model the gives the value of the car y (in dollars) in
t years.
B) What is the growth factor?
C) How much will the car worth in 2020?
D) How long will it take for my car to be worth double?
$5000 was invested at a bank 10 years ago at
12%.
What is the value of the investment now if the
bank compounds interest annually?
How much more would the value be if the bank
compounds monthly?investment be
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 year
b) a flat $15 a week raise for each successive year.
Which option is better? Show this by making an x-y
table showing the weekly salary for 10 years.
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
Practice Worksheet
y  P 1  r 
t
y  P 1  r 
t
Practice Worksheet
y  P 1  r 
t
y  P 1  r 
t