Straight Lines
Definition of Slope
The slope of a straight line passing through two points
(
x
1
,
y
1
)
and
(
x
2
,
y
2
)
is
m
=
y
2
−
y
1
x
2
−
x
1
This is also called
r
i
s
e
r
u
n
or
Δ
y
Δ
x
.
Forms of Equations of Lines
General Form:
A
x
+
B
y
=
C
Slope-intercept Form:
y
=
m
x
+
b
This line has slope
m
and
y
-intercept
(
0
,
b
)
.
*************************************
*************************************
Point-slope Form:
y
−
y
1
=
m
(
x
−
x
1
)
This line has slope
m
and passes through a specified point
(
x
1
,
y
1
)
.