1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply...

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1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus

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Transcript of 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply...

Page 1: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

1.4 Graphing Lines

If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain.

-Morpheus

Page 2: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Slope of a Line

x

y

x2 x1

y2 y1

P2(x2,y2)

P1(x1, y1)

m y2 y1

x2 x1

x1 x2

Page 3: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Slope of a Line

x

y

P2(11,6)

P1(2,3)

m y2 y1

x2 x1

x1 x2

Page 4: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Slope of a LineFind the slope of the line shown below.

Page 5: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Vertical and Horizontal LinesLet’s take a look at the vertical line and horizontal line through the point (-3,1).

Vertical Lines

Slope Undefined

x aEquation:

y b

Horizontal Lines

Slope = 0Equation:

Page 6: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Forms of a Line

y mx bSlope-Intercept Form:

y y1 m(x x1)Point-Slope Form:

Ax By CGeneral Form:

m = slope b = y-intercept

m = slope (x1,y1) = point on line

A,B are integers ≠ 0 and A > 0

Ex : y 12

x 3

Ex : y 3 12

(x 0)

Ex : y 2 12

(x 2)

Ex : x 2y 6

Page 7: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Forms of a Line - Practice1) Write the equation of the line in general form.

y 23

x 4

2) Write the equation of the line in slope-intercept form.

(y 2) 12

(x 1)

Page 8: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding Equations From GraphsFind the equation of the line. Write your answer in slope-intercept form.

Page 9: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding the Equation of a LineFind an equation for the line with the given properties. Express your answer in Slope-Intercept Form.

1) Slope = 2; containing the point (4,-3)

Page 10: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding the Equation of a LineFind an equation for the line with the given properties. Express your answer in General Form.

2) Containing the points (-3,4) and (2,5)

Page 11: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding the Equation of a LineFind an equation for the line with the given properties.

3) Slope undefined containing the point (3,8)

Page 12: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Parallel and Perpendicular Lines

Parallel Lines have slopes that are equal.

Perpendicular Lines have slopes that are opposite reciprocals.

Page 13: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding the Equation of a LineFind an equation for the line with the given properties. Express your answer in Slope-Intercept Form.

4) Parallel to the line 3x + y = 4; containing the point (-1,2)

Page 14: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Finding the Equation of a LineFind an equation for the line with the given properties. Express your answer in General Form.

5) Perpendicular to the line x - 2y = -5; containing the point (0,4)

Page 15: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

Graphing Lines in General FormWhen equations are in general form, we can use the intercepts to help us graph without solving for y.

2x 4y 8

Page 16: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

More Practice…before you get your homework, k?

1) Find the slope of the line containing the points (-2,-1) and (5,-6).

2) Find the slope and the y-intercept of the following lines.

2x 5y 10

(y 4) 34

(x 8)

3) Find the equation of the line below in slope-intercept form.

a) b)

Page 17: 1.4 Graphing Lines If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain. -Morpheus.

1.4 Graphing Lines

If real is what you can feel, smell, taste, and see, then “real” is simply electrical signals interpreted by the brain.

-Morpheus

Homework #14:Graphing Worksheet