Point plotting

Point plotting is an elementary <a href="/facts/Mathematics/pxTouaz4">mathematical</a> skill required in <a href="/facts/Analytic_geometry/3qWP0kM0">analytic geometry</a>. Invented by <a href="/facts/Ren%C3%A9_Descartes/ohqj6DMf">René Descartes</a> and originally used to locate positions on <a href="/facts/Military/kgNmLUnN">military</a> <a href="/facts/Map/KxQX4B2U">maps</a>, this skill is now assumed of everyone who wants to locate grid 7A on any map.
Using point plotting, one associates an <a href="/facts/Ordered_pair/EInLVI0r">ordered pair</a> of <a href="/facts/Real_number/R02gw5Pb">real numbers</a> (x, y) with a point in the <a href="/facts/Plane_(mathematics)/tAUtRFcn">plane</a> in a <a href="/facts/Bijection/j4gTuTmW">one-to-one</a> manner. As a result, one obtains the 2-dimensional <a href="/facts/Cartesian_coordinate_system/lkTqvMmB">Cartesian coordinate system</a>.
To be able to plot points, one needs to first decide on a point in plane which will be called the origin, and a couple of <a href="/facts/Perpendicular/u0k8xqx4">perpendicular</a> lines, called the x and y axes, as well as a preferred direction on each of the lines. Usually one chooses the x axis pointing right and the y axis pointing up, and these will be named the positive directions. Also, one picks a segment in the plane which is declared to be of unit length. Using rotated versions of this segment, one can measure distances along the x and y axes.
Having the origin and the axes in place, given a pair (x, y) of real numbers, one considers the point on the x axis at distance |x| from the origin and along the positive direction if x≥0, and the other direction otherwise. In the same way one picks the point on the y axis corresponding to the number y. The line parallel to the y axis going through the first point and the line parallel to the x axis going through the second point will intersect at precisely one point, which will be called the point with coordinates (x, y).

Point plotting open-in-new

Point plotting