Name the domain and range for the relation shown in each graph

D = {x | x is a real number}

R = {y | y ≥ -2}

D = {x | x is a real number}

R = {y | y ≥ 0}

Which of these represent linear functions?

linear

nonlinear

linear

nonlinear

In a linear equation, each term is either a constant or the product of a constant and (the first power of) a single variable.

Slope-intercept form

y = mx + b

f(x) = mx + b

m is the slope of the line

b is the y-intercept

What are the slope and y-intercept of the line ? Slope = 3

y-intercept = -9

Graph the line y-intercept = -9

Slope = 3

Slope = Δy Δx

The graph of a linear equation is a line.

Standard form Ax + By = C

• A, B and C are integers (not fractions!)

• A is positive

• A and B are not both zero

3x + 5y = -2 is in standard form

Write the equation in standard form. Identify A, B, and C.

Ax + By = C

Simplified?

2 2 2

Write the equation in standard form. Identify A, B, and C.

Simplified?

Ax + By = C

Write the equation in standard form. Identify A, B, and C.

Simplified?

Ax + By = C

-3 (-3)

Find the x- and y- intercepts of -2x + y – 4 = 0

x-intercept

-2x + 0 – 4 = 0

-2x – 4 = 0

-2x = 4

x = -2

The x-intercept is -2

(-2, 0)

y-intercept

-2(0) + y – 4 = 0

0 + y – 4 = 0

y – 4 = 0

y = 4

The y-intercept is 4

(0, 4)

x-intercept : –2

y-intercept: 4

(0, 4)

(–2, 0)

Graph -2x + y – 4 = 0