Graphing 21 - Writing Equation from two points 1

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Taught by YourMathGal
  • Currently 4.0/5 Stars.
8946 views | 1 rating
Part of video series
Meets NCTM Standards:
Lesson Summary:

This video covers how to write the equation of a line if you know two points on the line, providing two methods for doing so. The first method is to graph the two points and carefully draw the line, then determine the slope and y-intercept. The second method is to use the formula for slope to determine the slope of the line and then use the slope point formula or plug in an ordered pair, x and y, and the slope to solve for b. The video provides examples of both methods and emphasizes the importance of checking that the equation works for both given points.

Lesson Description:

Covers how to write the equation of a line if you know two points on the line. This is part 21 of a series of videos about graphing lines.

More free YouTube videos by Julie Harland are organized at http://yourmathgal.com

Questions answered by this video:
  • How do you write the equation of a line if you know two points on the line?
  • How do you find the equation of a line that passes through two points by graphing?
  • How do you write the equation of a line that passes through (-2, 1) and (2, -5) by graphing?
  • How do you find the slope and y-intercept of a line from two points on the line?
  • How do you find the slope between the points (-2, 1) and (2, -5) using the slope formula?
  • How do you find the equation of a line that passes through two points by using the slope formula and point-slope form?
  • How do you write the equation of a line in slope-intercept form that passes through (-2, 1) and (2, -5) by using the slope formula and point-slope form?
  • Does it matter which ordered pair you plug into the formula to find the equation of the line that passes through two points?
  • How can you re-write an equation that is in slope-intercept form in standard form?
  • How can you check to make sure that the equation of a line you find is correct?
  • Staff Review

    • Currently 4.0/5 Stars.
    This video covers writing the equation of a line given just two points on the line. This requires the largest amount of work to get to the equation compared with other lessons. All steps of a couple of different methods are explained in this very good, detailed video.