Exponential Functions (Growth/Decay)

Graphing ExponentialFunctions

100

Name at least one piece of information needed to graph an exponential functional functions 

* Y-intercept

* Growth/Decay value 

200

Identify the y-intercept and growth/decay factor 

  y=(5)^x

y-intercept: 1

Growth factor: 5

300

Graph the following exponential 

y= 3(2)^x

CALL MS. SIMMS 

400

Graph the following equation

y=(1/4)^x

CALL MS. SIMMS 

Creating an Exponential Equations

100

Given a table identify at least one thing you need in order to find the equation 

* growth/decay factor 

* starting value

200

Create the equation given the following table

x    y

-1   1/4

0    1

1    4

2    16

y=4^x

300

Find the equation given the table

x    y 

-2   16

-1     8

0      4

1      2

2       1

y=4(1/2)^x

400

Find the equation given the table 

x    y

-1     5

0      2

1      0.8

2      0.32

y=2(0.4)^x

Identify Parts

100

Identify the y-intercept

y=0.34(1.58)^x

y-intercept is 0.34

200

Determine if it is growth or decay then identify the factor 

y=1.45(6/5)^x

Growth

Factor: 6/5 

300

Identify the initial value 

The population in the town of Huntersville is presently 38,300. The town grows at an annual rate of 1.2%.

initial value 38,300

400

Identify if it is growth or decay then identify the factor

The population in the town of Huntersville is presently 38,300. The town grows at an annual rate of 1.2%.

Growth

Factor 1.012

Growth/Decay Word Probs

100

Write an equation if the starting value is 1567 and the growth is 20%

y=1567(1.2)^x

200

Write an equation of the initial value is 20197 and decays by 15.3% each time 

y=20197(0.847)^x

300

Your bank account starts with $1500 and has an annual rate of 5.6%. Write an equation to model the situation. 

y=1500(1.056)^x

400

You buy a new computer for 2100. The computer's value decreases by 38% annually. Write an equation to model the situation. 

y=2100(0.62)^x

Per. 7 ONLYCompound Interest

100

Identify what each the following represent when finding compound interest 

A=

P=

r=

n=

t=

A= account

P= principal (starting value)

r= rate as a decimal

n= times per year

t= number of years 

200

Determine the number of times per year each of the following occur.

annually

semiannually

quarterly

monthly

weekly

daily

annually =1 

semiannually = 2

quarterly = 4

monthly = 12

weekly= 52

daily = 365

300

Supposed you invested $1000 in a savings account at an 8% interest rate compounded monthly. Write BUT DO NOT SOLVE an equation to model the situation after 10 years.

A=(1+ 0.08/12)^(12)(10)

400

How long would it take for an investment of $1000 to double in value if it earns 5% compounded weekly? (Note: Write an equation to solve this problem, but solve the equation graphically, not algebraically.)

about 13-14 weeks