Find the slope of the line

Question

How do I find the slope of 3 points

Answer 1

Hi Ashley,

 

You only need two points in order to determine the slope of a line because 2 points create exactly one a line. If all 3 points are on the same line, then you only need to use 2 of them in the slope formula. If they are not on the same line, then you will have to carry out the slope equation 3 times, 1 for each pair of coordinates because they will create 3 different lines. Remember that the slope equation is (y₂ - y₁)/(x₂-x₁). It's helpful to label your coordinates. For example, if you have the points (1,-2) and (4,5), then y₁=-2, x₁=1, y₂=5, and x₂=4. When we substitute, our slope = (5- -2)/(4-1)=(5+2)/(4-1)= 7/3.

Answer 2

If you have two points, one line passes through them.

if you have three or more points, it's possible that they are all collinear--otherwise, pick any two points, and find their slope. Different slopes may be obtained for different combinations of points.