Bellwork: Use the slope formula to find the slope. y2 - y1 x2 - x1 m = 1.) (6,8) & (0,-5) 2.) (4,-3) & (4, 9) 3.) (8,3) & (-1,3) 4.) (2,3) & (8, -3)

Bellwork: Use the slope formula to find the slope. 1.) (6,8) & (0,-5) m = 13/6 2.) (4,-3) & (4, 9) m = 12/0 = undefined

Bellwork: Use the slope formula to find the slope. 3.) (8,3) & (-1,3) m = 0/-9 = 0 4.) (2,3) & (8, -3) m = -6/6 = -1

Do the 6 graphs worksheet for review. Classwork #1 Do the 6 graphs worksheet for review.

Classwork #2 Do worksheet 5.1 (13-18)

Write an equation of the line using the point-slope form. Today’s Objective Write an equation of the line using the point-slope form.

Equations of Lines Vertical line x = # Horizontal line y = # Slope, y-intercept y=mx+b Point, Slope y-y1=m(x-x1) Standard Form Ax+By = C

Converting the slope formula to the point-slope form Multiply both sides by (x2 - x1) m(x2 - x1) = (y2 - y1) (y2 - y1) = m(x2 - x1) y2 - y1 x2 - x1 m =

Consider A line containing the point (x1,y1) = (2,5) with a slope of 2/3. Let (x,y) be any other point on the line. (see the graph)

Point =(2,5) ,Slope = 2/3 Y (x,y) (x1,y1) X

Write an equation of the line Using the point-slope form if the point (x1,y1) = (2,5) and the slope is . y - y1 = m(x - x1) Point-Slope Form Substitute point & slope in for (x1,y1) y - 5 = (x - 2)

y = x + 3 2/3 y-5= x - 4/3 y - y1 = m(x - x1) y - 5 = (x - 2) Point-Slope Form Substitute Point & slope in for (x1,y1) Distribute  to (x -2) y-5= x - 4/3 y - 5 + 5= x-4/3+ 5 Add 5 to both sides. y = x + 3 2/3 The equation of the line.

Point =(2,5) ,Slope = 2/3 Y X y = x + 3 2/3

Write an equation of the line Using the point-slope form if the point (x1,y1) = (2,3) and the slope is -½. y - y1 = m(x - x1) Point-Slope Form Substitute point & slope in for (x1,y1) y - 3 = -½(x - 2)

y =-½x + 4 y - 3 =-½x + 1 y - y1 = m(x - x1) y - 3 = -½(x - 2) Point-Slope Form Substitute Point & slope in for (x1,y1) Distribute -½ to (x -2) y - 3 =-½x + 1 y - 3 + 3=-½x + 1+ 3 Add 3 to both sides. y =-½x + 4 The equation of the line.

Point =(2,3) ,Slope =-½ Y X y =-½x + 4

Write an equation of the line Now pick a point Using the point-slope form if the point (x1,y1) = (-3,6) and the point (x2,y2)=(1,-2) y2 - y1 x2 - x1 -2 - 6 1 - -3 -8 4 m = -2

y =-2x + 0 y - 6 =-2x - 6 y - y1 = m(x - x1) y - 6 = -2(x - -3) Point-Slope Form Substitute Point & slope in for (x1,y1) Distribute -2 to (x +3) y - 6 =-2x - 6 y - 6 + 6=-2x -6 + 6 Add 6 to both sides. y =-2x + 0 The equation of the line.

Write an equation of the line You try these 1.) (x1,y1) = (-1,2) slope = -1 2.) (x1,y1) = (1,3) slope = 1/3

Write an equation of the line 1.) (x1,y1) = (-1,2) slope = -1 y - y1 = m(x - x1) y - 2 = -1(x - -1) y - 2 = -x -1 y = -x +1

Write an equation of the line 2.) (x1,y1) = (1,3) slope = 1/2 y - y1 = m(x - x1) y - 3 = 1/2(x - 1) y - 3 = 1/2x - 1/2 y = 1/2x+5/2

Write an equation of the line You try these Write an equation of the line 3.) (x1,y1) = (0,2) (x2,y2) = (3,-2) 4.) (x1,y1) = (5,0) (x2,y2) = (0,-3)

Write an equation of the line 3.) (x1,y1) = (0,2) (x2,y2) = (3,-2) m= (-2-2)/(3-0) = -4/3 y - -2 = -4/3(x - 3) y + 2 = -4/3x + 4 y = -4/3x + 2

Write an equation of the line 4.) (x1,y1) = (5,0) (x2,y2) = (0,-3) m= (-3-0)/(0-5) = 3/5 y - 0 = 3/5(x - 5) y - 0 = 3/5x - 3 y = 3/5x - 3

Classwork Do worksheet 5.6 homework page 274 (1-5 & 9-18)