NAME
7-5
DATE
PERIOD
Word Problem Practice
Exponential Functions
1. WASTE Suppose the waste generated
by nonrecycled paper and cardboard
products is approximated by the
following function.
y = 1000(2)0.3x
Sketch the exponential function on the
coordinate grid below.
2450
2150
1850
1550
1250
950
650
350
y
$1994
1 2 3 4x
5. METEOROLOGY The atmospheric
pressure in millibars at altitude
x meters can be approximated by the
following function. The function is valid
for values of x between 0 and 10,000.
f (x) = 1038(1.000134)-x
2. MONEY Tatyana’s grandfather gave her
one penny on the day she was born. He
plans to double the amount he gives her
every day. Estimate how much she will
receive from her grandfather on the 12th
day of her life.
a. What is the pressure at sea level?
1038 millibars
about $20
3. PICTURE FRAMES
Since a picture frame
includes a border, the
picture must be
smaller in area than
the entire frame. The
table shows the
relationship between
picture area and frame
length for a particular
line of frames. Is this
an exponential
relationship? Explain.
b. The McDonald Observatory in Texas
is at an altitude of 2000 meters. What
is the approximate atmospheric
pressure there?
Side
Picture
Length
Area
(in.)
(in2)
5
6
6
12
7
20
8
30
9
42
794 millibars
c. As altitude increases, what happens to
atmospheric pressure?
It decreases.
Lesson 7 -5
Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc.
-4-3-2-1O
4. DEPRECIATION The value of Royce
Company’s computer equipment is
decreasing in value according to the
following function.
y = 4000(0.87)x
In the equation, x is the number of
years that have elapsed since the
equipment was purchased and y is the
value in dollars. What was the value
5 years after it was purchased? Round
your answer to the nearest dollar.
No; there is no common factor
between the picture areas.
Chapter 7
33
Glencoe Algebra 1