Whenever you look at a bridge or a building, you are seeing the results of coordinate geometry. If you figure out the shortest distance to travel between two points, you are using coordinate geometry. This mathematics discipline describes the position of points on a plane using an ordered pair of numbers. The point (3,4), for example, is located three spaces to the right and four spaces up from the center, or origin.

Cartesian Coordinates
Rene Descartes, a French philosopher in the early 1600s, created a system of coordinates using numerical values for the X, Y and Z axes. Using these coordinates, the position of any point can be expressed mathematically. All points are related to the origin (0,0), where the X and Y axes cross. To find the point (2,5), start at the origin and move two spaces to the right and five spaces up. The relationship of one point to another can be written as an equation, thus allowing for the mathematical description of a two-dimensional shape or three-dimensional object.

Coordinate Geometry in Scientific Experiments
Scientists use coordinate geometry to analyze the results of experimental data. In any scientific experiment, data collected for the independent and dependent variables is usually plotted on a graph. This graph uses Cartesian coordinates. The independent variable is plotted on the X axis and the dependent variable is plotted on the Y axis. By examining the patterns on a graph, scientists can draw conclusions about the relationship between the two variables. For example, if a scientist is observing the effect of fertilizer on plant growth, he would create a scale to represent the amount of fertilizer in milliliters on the X axis, and then a scale to represent the amount of plant growth in millimeters on the Y axis. The corresponding data points would then be plotted and connected.

Coordinate Geometry in Physics
Physicists use coordinate geometry to describe the motion of objects. In "Math and Physics for Games," an introductory course taught at Johnson County Community College, students use coordinate geometry to model the motion of objects in the video game world. Forces and motion are important components and can be plotted on a graph of Cartesian coordinates like other experimental data. For example, the distance of an object from a particular point over time can be graphed on the X and Y plane. Physicists use the graph's slope to gain additional information.

Coordinate Geometry in Engineering and Architecture
Engineers and architects use coordinate geometry to represent points, lines, shapes and surfaces as algebraic expressions with letters and numbers. This allows them to perform the calculations required to design a complex structure, such as a bridge or building. Such calculations include stress, moment of inertia, and tensile strength. For example, a structural engineer may measure the dimensions of a beam in order to calculate the maximum load, or stress, the beam can support. This is essential information when planning the infrastructure of a building.


Source: http://www.ehow.com/info_10042688_coordinate-geometry-used-for.html