Download 3-5 Lines in the coordinate plane M11.B.2 2.3.11.A Objectives: 1)To

3-5 LINES IN THE
COORDINATE PLANE
M11.B.2 2.3.11.A
OBJECTIVES:
1)TO GRAPH LINES GIVEN THEIR
EQUATIONS
2) TO WRITE EQUATIONS OF LINES
Vocabulary

The slope-intercept form of a linear equation is
y = mx + b, where m is the slope of the line
and b is the y-intercept.
Example:
Y = 2x + 3
Y = 2x – 1
Y = 2x – 4

Example: Graph Lines in SlopeIntercept Form

y = -2x + 4

y = ½ x -3

y=¾x
Vocabulary

Standard Form of a Linear Equation – is
Ax + By = C, where A, B, and C are real
numbers, and A and B are not both zero.
Example: Find A, B and C.
-3x + 2y = 12

Example: Graphing Lines Using Intercepts


Use the x and y intercept to graph 4x – 6y =24
“Hide and Divide”
Example:
Graphing Lines Using Intercepts

Graph -2x + 4y = -8

Graph 5x – 6y = 30
Example: Transforming from Standard
Form to Slope-Intercept Form

Graph -6x + 3y = 12
Graph using Slope-Intercept Form

-5x + y = -3

-6x – 3y = 12
Vocabulary

Point – Slope form – used for a nonvertical line
through point (x₁ , y₁) where m = slope.
y – y₁ = m( x – x₁)
Example: Using Point – Slope Form

Write an equation of the line through point (3, 6)
and with a slope of -8.
Using Point-Slope Form
Example:
Write an equation of the line with slope -1 that
contains point P(2, -4)

Slope Formula

Given two points: (x1, y1) and (x2, y2)
m = y2 – y1
x2 – x1
Example: Find the slope of (3, -2) and (-5, 6)
Example: Equation of a Line Given Two Points

Write an equation of the line through points
G( 4, -9 ) and H( -1, 1).
Equation of a Line Given Two Points

Write an equation of the line that contains the
points P(5, 0) and Q(7, -3).
Slopes of Special Lines

What is the slope of a horizontal line and a vertical
line?
Example: Equation of Horizontal & Vertical Lines

Write equations for the horizontal line and the
vertical line that contains P(3, 2).
Equations of Horizontal and Vertical Lines

Write equations of the horizontal and vertical lines
that contain the point P(5, -1)