scaleto denote the brightness of objects in the
sky. The brighter an object appears to an observer
on Earth, the more negative is its apparent
magnitude. Graph each of the following on
the scale to the right.
- Visual limit of binoculars
- Visual limit of large telescope
- Visual limit of naked eye
- Full moon
- Pluto
- Sirius (a bright star)
- Sun
- Venus
- LINE GRAPHS Each thermometer in the
illustration gives the daily high temperature in
degrees Fahrenheit. Use the data to complete
the line graph below.
15 °
10 °
5 °
− 5 °
− 10 °
− 15 °
0 °
Mon.
Temperat
ure
(Fahrenheit)
Tue. Wed.
Line graph
Thu. Fri.
Mon. Tue.
− 15 °
Wed.
− 10 °
− 5 °
0 °
5 °
10 °
Thu. Fri.
4
26
2
15
12
6
20
10
2.1 An Introduction to the Integers 143
B.C. 800 600 400 200 0 200 400 600 800 A.D.
Romans
conquer
Greece 146
Muhammad
begins
preaching 610
Buddha
born 563
First
Olympics
776
Han
Dynasty
begins
202
Jesus
Christ
born
Mayans
develop
advanced
civilization
250
Ghana
empire
flourishes
mid-700s
a. What basic unit is used to scale this time line?
b. What can be thought of as positive numbers?
c. What can be thought of as negative numbers?
d. What important event distinguishes the positive
from the negative numbers?
- ASTRONOMY Astronomers use an inverted
vertical number line called the apparent magnitude
a. In what years did Amazon suffer a loss? Estimate
each loss.
b. In what year did Amazon first turn a profit?
Estimate it.
c. In what year did Amazon have the greatest profit?
Estimate it.
- HISTORY Number lines can be used to display
historical data. Some important world events are
shown on the time line below.
–600
–400
–200
200
0
400
$ millions
–800
–1,000
–1,200
–1,400
–1,600
Amazon.com
Net Income
600
800
'00 '01 '02
'03 '04 '05 '06 '07
Year
'98 '99
Bri
ght
Dim
–25
–20
–15
–10
–5
0
5
10
15
20
25
Apparent ma
gnit
ude
