3-6 Lines in the Coordinate Plane 3-6 Lines in the Coordinate Plane

3-6 Lines in the Coordinate Plane
3-6 Lines in the Coordinate Plane
Lesson Presentation
Lesson Quiz
Holt McDougal Geometry
Geometry

3-6 Lines in the Coordinate Plane
Objectives
Graph lines and write their equations in
slope-intercept and point-slope form.
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
The equation of a line can be written in
many different forms. The point-slope and
slope-intercept forms of a line are
equivalent. Because the slope of a vertical
line is undefined, these forms cannot be
used to write the equation of a vertical line.
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Remember!
A line with y-intercept b contains the point (0, b).
A line with x-intercept a contains the point (a, 0).
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Example 1A: Writing Equations In Lines
Write the equation of each line in the given
form.
the line with slope 6 through (3, –4) in pointslope
form
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Example 1B: Writing Equations In Lines
Write the equation of each line in the given form.
the line through (–1, 0) and (1, 2) in slopeintercept
form
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Example 1C: Writing Equations In Lines
Write the equation of each line in the given form.
the line with the x-intercept 3 and y-intercept
–5 in point slope form
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Check It Out! Example 1a
Write the equation of each line in the given form.
the line with slope 0 through (4, 6) in slopeintercept
form
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Graph each line.
Example 2A: Graphing Lines
rise 1
run 2
(0, 1)
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Example 2B: Graphing Lines
Graph each line.
y – 3 = –2(x + 4)
(–4, 3)
rise –2
run 1
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Example 2C: Graphing Lines
Graph each line.
y = –3
x = 5
(0, –3)
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Check It Out! Example 2b
Graph each line.
(–2, 1)
rise –2
run 3
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
Lesson Quiz: Part I
Write the equation of each line in the given
form. Then graph each line.
1. the line through (-1, 3)
and (3, -5) in slopeintercept
form.
Holt McDougal Geometry

3-6 Lines in the Coordinate Plane
2. the line through (5, –1)
with slope in point-slope
form.
Holt McDougal Geometry