WIR Math 166-copyright Joe Kahlig, 05B
Page 1
Week in Review # 1
Section 1.1 and 1.2: Graphs and Lines
•
x and y axis, origin
•
ordered pair: (x,y)
•
distance formula
d
=
q
(
x
2
-
x
1
)
2
+ (
y
2
-
y
1
)
2
•
slope formula
m
=
y
2
-
y
1
x
2
-
x
1
•
equations of lines
•
slope intercept:
y
=
mx
+
b
•
point slope:
y
-
y
1
=
m
(
x
=
x
1
)
•
Horizontal line thru the point (a,b) is
y
=
b
•
Vertical line thru the point (a,b) is
x
=
a
•
Slopes of parallel lines are equal.
•
Slopes of perpendicular lines are negative reciprocals.
1. Which point, A(3,7) or B(9, 22), is closer to the point C(8,14)?
2. Find the equation of the line thru the point C(8,14) that is parallel to the line through
points A(3,7) and B(9, 22).
3. Find the equation of the line thru (7,10) and perpendicular to 7
x
+ 4
y
= 21
4. Find the equation of the line that crosses the x-axis at 7 and the y-axis at
-
8
WIR Math 166-copyright Joe Kahlig, 05B
Page 2
5. Find the value(s) of
a
so that the line thru the points B(a, 1) and C(2, 5) is perpen-
dicular to the line thru the points D(1, 2) and E(4, a+2).
