Basic Algebra/Lines (Linear Functions)/Find the Equation of the Line Using Two Points< Basic Algebra
You can find the y intercept(b) of a line by using "point slope" with a pair of cordinates.
-Find the slope (y2 - y1) / (x2 - x1) -Use one of the coordinates (points) and use this formula: y-y1=m(x-x1) -Then you end up with y=mx+b
Find the y-intercept of the following coordinates:
(0,2) Example 1:
First find the slope m of between the two points:
m = (y-y1) / (x-x1)
m = (6-2) / (3-5)
m = -2 ' We know that the equation has the form y = mx + b, and we also know that this function passes both of the points, so let's use point #1 to find b:
point #1 (2,1)
2 = m(5) + b
2 = (-2)(5) + b
b = 12
Alternatively, we can use point #2 and get to the same result.
The line equation is:
y = -2x + 12