Question 545238: Find the Equation of a Line Given That You Know Two Points it Passes Through.
(1/2,-3) and (-2,1)
Thank you
Answer by KMST(5396)   (Show Source):
You can put this solution on YOUR website! When you know two points in a line, you can calculate the slope. Then, with the slope and just one point, you can write the equation of the line.
The slope (usually represented by m) can be calculated as the difference in y coordinate, divided by the difference in x coordinate (also called rise and run). So,
 is the run, the increase in x as you go from (-2,1) to (1/2,-3)
 is the rise, how much y rises as you go from (-2,1) to (1/2,-3), and you know that it goes down by 4, so the rise is -4.
With the slope (m) and one point (h,k), you can write the equation of the line in the point-slope form as
So, using point (-2,1),
 <-->
And we can transform that equation into the slope-intercept form like this:
 <-->
|
|
|
