1 / 15

2.4 Writing the Equation of a Line

2.4 Writing the Equation of a Line. Review of Slope-Intercept Form. The slope-intercept form of a linear equation is y = mx + b. m represents the slope b represents the y-intercept. Review of Slope-Intercept Form. Name the slope and y-intercept of each equation :. y = -4 x + 3

fabrizio
Download Presentation

2.4 Writing the Equation of a Line

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. 2.4 Writing the Equation of a Line

  2. Review of Slope-Intercept Form The slope-intercept form of a linear equation is y = mx + b. m represents the slope b represents the y-intercept

  3. Review of Slope-Intercept Form Name the slope and y-intercept of each equation: y = -4x + 3 y = 5 – x 8x + y = 4x - 2y =10 y = x y = 5 m = -4, b =3 m = - , b = 5 Rewrite as y = -8x , m = -8, b = Rewrite as y = 2x - 5, m = 2, b = -5 Rewrite as y = x + 0, m = , b = 0 Rewrite as y = 0x + 5, m = 0, b = 5

  4. Write the equation of a line given... 1. Slope and y-intercept 2. Graph 3. Slope and one point 4. Two points 5. x - and y-intercepts

  5. m = -3, b = 1 m = -2, b = -4 m = 0, b = 10 m = 1, b = 0 m = 0, b = 0 Find the Equation of the LineGiven the Slope and y-intercept • Substitute m and b intoy = mx + b y = -3x + 1 y = -2x - 4 y = 0x + 10, y = 10 y = 1x + 0, y = x y = 0x + 0, y = 0

  6. Find the Equation of a LineGiven the Graph • Find the y-intercept from the graph. • Count the slope from the graph. • To write the equation of the line, substitute the slope and y-intercept in the slope-intercept form of the equation.

  7. +2 +3 x y Example 1 • b = -3 • m = • y = x - 3

  8. -2 +1 x y Example 2 • b = 1 • m = • y = x + 1

  9. x y Example 3 • b = 4 • m = 0/1= 0 • y = 0x + 4, y = 4

  10. Find the Equation of a LineGiven the Point and the Slope • Use the Point-Slope Formula: • is the given point • Substitute m and into the formula

  11. Example • Write the equation of the line with slope = -2 and passing through the point (3, -5). • Substitute m and into the Point-Slope Formula.

  12. Find the Equation of the LineGiven Two Points • Calculate the slope of the two points. • Use one of the points and the slope to substitute into the Point-Slope formula.

  13. Example • Write the equation of the line that goes through the points (3, 2) and (5, 4).

  14. Find the Equation of the LineGiven the x- and y - intercepts • Write the intercepts as ordered pairs. The x-intercept 4 is the ordered pair (4, 0). The y-intercept -2 is the ordered pair (0, -2). • Calculate the slope. • Substitute the slope and the y-intercept (b) into the slope-intercept formula.

  15. Example Write the equation of the line with x-intercept 3 and y-intercept 2. x-intercept 3 = (3, 0); y-intercept 2 = (0, 2) Slope: y = mx + b

More Related