BEFORE: NOVEMBER 1, 2017 Identify whether each represents a linear function. 1. 2. X Y -1 -3 -2 1 2 3

DURING: USING INTERCEPTS FIND X- FIND X- AND Y-INTERCEPTS LEARNING TARGET: I CAN… GRAPH LINEAR EQUATIONS

KEY VOCABULARY The x-intercept is the x-coordinate of the point where the graph intersects the x-axis. The y-coordinate of this point is always 0. The y-intercept is the y-coordinate of the point where the graph intersects the y-axis. The x-coordinate of this point is always 0.

FINDING INTERCEPTS – “I DO” Find the x- and y- intercepts.

FINDING INTERCEPTS – “WE DO” Find the x- and y- intercepts.

FINDING INTERCEPTS-- “YOU DO” Find the x- and y- intercepts.

STANDARD FORM OF A LINEAR EQUATION Another way to determine whether a function is linear is to look at its equation. A function is linear if it is described by a linear equation. A linear equation is any equation that can be written in the standard form shown below. Ax + By = C Where A, B, and C are real numbers and A and B are not both 0.

Notice that when a linear equation is written in standard form x and y both have exponents of 1 x and y are not multiplied together x and y do not appear in denominators, exponents, or radical signs Ax + By = C

Finding Intercepts Using Standard Form

Finding Intercepts Using Standard From

FINDING INTERCEPTS – “I DO” Find the x- and y- intercepts. 3x – 2y = 12

FINDING INTERCEPTS – “WE DO” Find the x- and y- intercepts. -3x + 5y = 30

FINDING INTERCEPTS – “YOU DO” Find the x- and y- intercepts. 4x + 2y = 16

GRAPHING LINEAR EQUATIONS BY USING INTERCEPTS To graph a linear function, you need to plot only two ordered pairs. It is often simplest to find the ordered pairs that contain the intercepts. Step 1: Find the intercepts. Step 2: Graph the line.

GRAPHING LINEAR EQUATIONS BY USING INTERCEPTS – “I DO” 2x – 4y = 8

GRAPHING LINEAR EQUATIONS BY USING INTERCEPTS – “WE DO” y = -x + 4

GRAPHING LINEAR EQUATIONS BY USING INTERCEPTS – “YOU DO” -3x + 4y = -12

Graphing Ax + By = C Using Intercepts AFTER A function has x-intercept 4 and y-intercept 2. Name two points on the graph of this function. Copy and complete the graphic organizer: Graphing Ax + By = C Using Intercepts 1. Find the x-intercept by ______?________. 2. Find the y-intercept by ______?_______. 3. Graph the line by _______?_______

EXTRA PRACTICE Page 240 #s 3 – 12, multiples of 3