How do I find the y-intercept from two coordinates on a graph?
Answer (3)
P 1 = ( x 1 , y 1 ) an d P 2 = ( x 2 , y 2 ) P 1 P 2 : y = m x + b m = x 2 − x 1 y 2 − y 1 ⇒ y = x 2 − x 1 y 2 − y 1 ⋅ x + b f or P 1 : y 1 = x 2 − x 1 y 2 − y 1 ⋅ x 1 + b ⇒ b = y 1 − x 2 − x 1 y 2 − y 1 ⋅ x 1
Ex. (4,7) and (8,15) (15-7)/(8-4) 8/4 2
2 is your slope. To find the y-int plug in one of the coordinates into y=mx+b 7=(2)(4)+b 7=8+b -1=b In this example the y-int would be -1. This method will work for all points
To find the y-intercept from two coordinates, calculate the slope using the two points, then use the slope-intercept form of the line equation by substituting one of the points to solve for the y-intercept. This will give you the point where the line crosses the y-axis. Understanding this concept is essential in graphing linear equations.
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