# Can anyone teach me cartsian coordinates fully?please?

##### 1 Answer

Below is a short description of Cartesian coordinate system.

#### Explanation:

Cartesian coordinates are by far the most common type of coordinates used in mathematics.

To numerically identify a point on a line we fix one particular point called the beginning of the coordinates or *origin*, one particular direction on this line from the origin which we call the *positive direction* and some *unit of measurement* represented as a segment we set as having the length of

Now we are ready to put into correspondence for any point on this line a number that characterizes the distance from this point to the *origin* measured in the *units* we have set and with a *sign* depending on whether the point lies towards the positive direction from the origin or the opposite negative one. For a point positioned exactly at the origin this number is of course zero. This number is called a point's coordinate. Since we need just one number to identify a point on a line in our system, the line is called a **one-dimensional space**.

To identify a point on a plane, we have to fix a pair of mutually perpendicular lines usually called X-axis and Y-axis that divide a plane into four *quadrants*. On each of these lines we can set a one-dimensional Cartesian coordinates with the origin at a point of intersection of these lines. Each point on a plain can now be projected to both axes by dropping from it perpendiculars to them.

Now we have two projection points - one on the X-axis and another on the Y-axis. These projection points have one-dimensional coordinates on the corresponding axes. One is called X-coordinate or *abscissa*, another - Y-coordinate or *ordinate*. A pair of these coordinates constitute coordinates of the original point on a plane.

The quadrant with points having positive X- and Y-coordinates is called the first quadrant. Then other quadrants are numbered counterclockwise - second (negative X, positive Y), third (negative X, negative Y) and forth (positive X, negative Y). Since we need two numbers to identify a point on a plane, the plane is called a **two-dimensional space**.

To identify a point in our space where we live, the Cartesian coordinates are defined as a triplet of one-dimensional coordinates of projections of our point to three mutually perpendicular lines usually called X-axis, Y-axis and Z-axis sharing the origin. These three coordinates are called *abscissa* (on the X-axis), *ordinate* (on the Y-axis) and *applicate* (on the Z-axis). Since we need three numbers to identify a point in our space, our space is called **three-dimensional**.

Multi-dimensional spaces with more than three dimensions are also studied in mathematics. They have a limited visual representation but are very useful in solving many practical problems.

For more information you can go to UNIZOR Web site and examine the topic *Math Concepts - Coordinates*.