Presentation is loading. Please wait.

Presentation is loading. Please wait.

WHAT IS NEEDED: The slope and the y-intercept. An equation consists of…. y = mx + b Slope Y-intercept.

Similar presentations


Presentation on theme: "WHAT IS NEEDED: The slope and the y-intercept. An equation consists of…. y = mx + b Slope Y-intercept."— Presentation transcript:

1

2 WHAT IS NEEDED: The slope and the y-intercept. An equation consists of…. y = mx + b Slope Y-intercept

3  Using the slope-intercept form of a line y= mx + b 1.Plug in m(the slope) 2. Plug in b(the y-intercept). Presto, you have just written the equation of a line!

4  Example: Write an equation for a line that has slope of -1/2 and a y-intercept of 3. y = mx + b 1.Plug in m (the slope). y = -1/2x + b 2. Plug in b (the y-intercept).y = -1/2x + 3  Done!

5  Using the slope-intercept form of a line y= mx + b 1.Plug in m and plug in the point for x & y. 2. Solve for b 3. Write your equation with your m and b.

6  Write the equation of a line that has a slope of -2 and goes through the point (-2, -1). 1. Plug in m, x & y-1=-2(-2)+b 2. Solve for b.-1 = 4 + b, b = -5 3. Write equation with m & b y = -2x - 5

7  Using the slope-intercept form of a line y= mx + b 1. Remember that the slope of two parallel lines are the same so just use the slope of the line you are given. 2. Plug in m, x & y. 3. Solve for b. 4. Write your equation with your m and b.

8  Write an equation of a line that goes through the point (-5, 5) and is parallel to the line y = -8/5 x + 5. 1. Since the new line is parallel to the one given they have the same slope, m = -8/5. 2. Plug in m, x & y.5 = -8/5(-5) + b 3. Solve for b. b = -3 4. Write your equation with your m and b. y = -8/5 x - 3

9  Using the slope-intercept form of a line y= mx + b 1.Remember that the slope of two perpendicular lines are negative reciprocals, so find the negative reciprocal of the slope of the line given and use that as m. 2. Plug in m, x & y. 3.Solve for b. 4. Write your equation with your m and b.

10  Find an equation of a line that goes through the point (-4,2) and is perpendicular to y = 2x +4  1. The slope of this line is 2, the negative reciprocal would be -1/2. So that will be the slope you use in your equation.  2. Plug in m, x & y. 2= -1/2(-4) +b 0 = b  3. Solve for b.  4. Write your equation with your m and b. y = -1/2 x + 0

11  Using the slope-intercept form of a line y= mx + b  1. Find the slope between the two points.  2. Plug in the slope and either one of the points.  3. Solve for b.  4. Write your equation with m and b.

12  Write an equation of a line that goes through the points (0, -1) and (-3, 4).  1. Use the formula to find the slope of the line. m=-5/3  2. Plug in m, x & y. -1=-5/3(0) + b  3. Solve for b. -1 = b  Write your equation with your m and b. y = -5/3x -1


Download ppt "WHAT IS NEEDED: The slope and the y-intercept. An equation consists of…. y = mx + b Slope Y-intercept."

Similar presentations


Ads by Google