EQ: How can I graph linear functions? I will graph linear functions.

Functions, Equations, and

GraphsCh. 2.3

Linear Functions and Slope-Intercept Form

EQ: How can I graph linear functions? I will graph linear functions.

Bell Work

List the domain and range of the relation. Determine whether or not each relation is a function.

1. (3, -2), (4,4), (0,-2), (4,1), (3,2)

2. (3,-8), (-9,1), (3,2), (-4,1), (-11,-2)

Evaluate the function.

3. f(4) = 17x+3

EQ: How can I graph linear functions? I will graph linear functions.

Linear Functions and Slope-Intercept Form

READ

Although any two-variable equation can be graphed on a coordinate grid by plotting ordered pairs, there are often more efficient ways. The first step is to recognize the general shape of a graph from its equation. For example, the graph of y=3x^2 – 2 is a parabola and y = |x-2| is V-shaped. Graphs of linear equations are straight lines. There are various forms for these equations (standard, slope-intercept, point-slope, and intercept form).

EQ: How can I graph linear functions? I will graph linear functions.

Slope-Intercept Form

• https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/8th-slope-intercept-form/v/graphing-a-line-in-slope-intercept-form

EQ: How can I graph linear functions? I will graph linear functions.

Finding Slope

What is the slope of the line that passes through the given points?

a. (-3,7) and (-2,4)

b. (3,1) and (-4, 1)

c. (7,-3) and (7,1)

EQ: How can I graph linear functions? I will graph linear functions.

Finding Slope

Now you try…

What is the slope of the line that passes through the given points?

a. (5,4) and (8,1)

b. (2,2) and (-2,-2)

c. (9,3) and (9, -4)

EQ: How can I graph linear functions? I will graph linear functions.

Slope of a line

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Writing Linear Equations

Slope-intercept form: y=mx+b

What is the equation of each line?

1. m=1/5, and the y-intercept is (0,-3)

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Writing Linear Equations

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Writing Linear Equations

Now you try…

What is the equation of the line?

a. m= 6, y-intercept is (0,5)

EQ: How can I graph linear functions? I will graph linear functions.

Writing Linear Equations

Now you try…

EQ: How can I graph linear functions? I will graph linear functions.

Writing Equations in Slope-Intercept Form

5x-4y=16

EQ: How can I graph linear functions? I will graph linear functions.

Writing Equations in Slope-Intercept Form

Now you try…

a. 3x + 2y = 18

b. -7x – 5y = 35

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Graphing a Linear Equation

What is the graph of -2x + y = 1?

EQ: How can I graph linear functions? I will graph linear functions.

Graphing a Linear Equation

Now you try…

What is the graph of 4x – 7y = 14

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Homework!

Workbook page 35-36, 2-24 EVEN

EQ: How can I graph linear functions? I will graph linear functions.

Closure

(On your bell sheet)