# Do Now 6/3/10 Take out HW from last night. Take out HW from last night. Text p. 407, #8-10, 12-30 evens Text p. 407, #8-10, 12-30 evens Copy HW in your.

## Presentation on theme: "Do Now 6/3/10 Take out HW from last night. Take out HW from last night. Text p. 407, #8-10, 12-30 evens Text p. 407, #8-10, 12-30 evens Copy HW in your."— Presentation transcript:

Do Now 6/3/10 Take out HW from last night. Take out HW from last night. Text p. 407, #8-10, 12-30 evens Text p. 407, #8-10, 12-30 evens Copy HW in your planner. Copy HW in your planner. Text p. 415, #10-12, 14-18 evens Text p. 415, #10-12, 14-18 evens Quiz sections 8.3-8.5 Tuesday Quiz sections 8.3-8.5 Tuesday In your notebook, identify the slope of each colored line. The black lines are the x-and y-axis. In your notebook, identify the slope of each colored line. The black lines are the x-and y-axis. Positive slope Negative slope Slope of 0 Undefined

Homework Text p. 407, #8-10, 12-30 evens 8) positive; 3/4 8) positive; 3/4 9) negative; -3/4 9) negative; -3/4 10) undefined 10) undefined 12) (0,-1) & (2, -1); m = 0 12) (0,-1) & (2, -1); m = 0 14) (6,0) & (0,3); m = -1/2 14) (6,0) & (0,3); m = -1/2 16) (3,0) & (3,5); m = undefined 16) (3,0) & (3,5); m = undefined 18) 18) 20) 20) 22) 2 22) 2 24) undefined 24) undefined 26) 7/8 26) 7/8 28) -5 28) -5 30) undefined 30) undefined

Objective SWBAT graph linear equations using slope-intercept form SWBAT graph linear equations using slope-intercept form

Section 8.4 “The Slope of a Line” SLOPE- the ratio of the vertical change (the rise) to the horizontal change (the run) between any two points on a line. Slope = rise = change in y run change in x

Slope Review The slope m of a line passing through two points and is the ratio of the rise change to the run. and is the ratio of the rise change to the run. y x run rise

Section 8.5 “Graph Using Slope- Intercept Form” SLOPE-INTERCEPT FORM- a linear equation written in the form y = mx + b slopey-intercept y-coordinatex-coordinate

Identifying Slope and the Y-Intercept y = 3x + 4 3x + y = 2 The equation is in the form y The equation is in the form y = m x + b. So, the slope of the line is 3, and the y- intercept is 4. Rewrite the equation in slope-intercept form by solving for y. y = mx + b y = -3x + 2 y = 2 – 3x The line has a slope of – 3 and a y- intercept of 2. Is this in slope-intercept form? Slope of 3 means:

Identify the slope and y- intercept of the line with the given equation. 3x – 3y = 12 ANSWER The line has a slope of 1 and a y- intercept of –4. Rewrite the equation in slope-intercept form by solving for y. Divide 3 by equation. 3x – 12 = 3y = 3y Rewrite original equation. y 3x – 12 3x – 12= 3 y x – 4 x – 4= Simplify.

Write an equation for the line. y = x – 1 slopey-intercept Slope of 1/1 means: 1/1 means: y-intercept = -1 Slope = 1/1 y = mx + b

1 2 3 4 5 0123456 y-axis x-axis -6-5-4-3-2 -5 -4 -3 -2 Graph an Equation Using the Slope-Intercept Form Graph the equation y = 2 - 2x. Rewrite in slope-intercept form slopey-intercept Slope of -2 means: -2 means: Slope of -2 means: -2 means: OR

1 2 3 4 5 0123456 y-axis x-axis -6-5-4-3-2 -5 -4 -3 -2 Graph an Equation Using the Slope-Intercept Form Graph the equation y = -3 + 2/3x. Rewrite in slope-intercept form slopey-intercept Slope of 2/3 means: 2/3 means: Slope of 2/3 means: 2/3 means: OR

Graph Using Slope and the Y- Intercept Graph the equation 2x + y = 3. STEP 1 Rewrite the equation in slope-intercept form. y – 2x + 3 = Identify the slope and the y- intercept. STEP 2 STEP 3 Plot the point that corresponds to the y- intercept, (0, 3). STEP 4 Use the slope to locate a second point on the line. Draw a line through the two points. = – 2 m and = 3 b Slope of -2 means:

Graph Using Slope and the Y- Intercept Graph the equation 3y – 2x = 3. STEP 1 Rewrite the equation in slope-intercept form. Identify the slope and the y- intercept. STEP 2 STEP 3 Plot the point that corresponds to the y- intercept, (0, 1). STEP 4 Use the slope to locate a second point on the line. Draw a line through the two points. = 2/3 m and = 1 b y = + 1 y = + 123 x Slope of 2/3 means:

Parallel Lines two lines in the same plane are parallel if they never intersect. Because slope gives the rate at which a line rises or falls, two lines with the SAME SLOPE are PARALLEL. y = 3x + 2 y = 3x – 4

Perpendicular Lines two lines in the same plane are perpendicular if they intersect at right angles. Because slope gives the rate at which a line rises or falls, two lines with slopes that are NEGATIVE RECIPROCALS are PERPENDICULAR. y = -2x + 2 y = 1/2x – 4 ½ and -2 are negative reciprocals. 4/3 and -3/4 are negative reciprocals.

Determine which of the lines are parallel. Find the slope of each line. Line a: m = – 1 – 0 – 1 – 2 – 3 – (–1 ) 0 – 5 = – 1– 1– 1– 1 – 3– 3– 3– 3 13 = Line b: m = – 2– 2– 2– 2 – 5– 5– 5– 5 = 2 5 = Line c: m = – 5 – (–3) – 2 – 4 – 2– 2– 2– 2 – 6– 6– 6– 6 = 1 3 = Line a and line c have the same slope, so they are parallel.

Homework Text p.247 #4-38 even Guided Practice Worksheet Form C odds

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