User:Mdl kid

= News = ---

March 20th 2006
I have just created my account and I am going to add Vector Calculus information to help myself remember it.

= Contributations = --

Finding Directional Vector
First start out finding the direction vector. To find the directional vector with 2 points, ex: (-1, 19) and (5, 11) you use the idea of the slope formula (y2 - y1)/(x2 - x1). With this you get the vector (-1 - 5)i + (19 - 11)j.

Finding the Vector
To find the vector you now use one of the points(-1, 19) and the directional vector (-6i + 8j). By putting them together you get (-1i + 19j) + t(-6i + 8j), then re-arranging we come up with the following vector:

(-6t - 1)i + (8t + 19)j

Check if other points are on the line
Now we check to make sure all of the points are on the line. To do this simply set your vector equal to the other points (one at a time) and test wether they equal each other at any time (t).

For example:

(-6t - 1)i + (8t + 19)j = (5i + 11j) at (t) = -1 Therefore the point (5, 11) is on the line.