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Vector and Operations

Position Vector

Nabil Akbarazzima Fatih

Mathematics

Definition of Position Vector

A position vector is a vector that starts from point O (origin) in a coordinate system and ends at another point. This vector plays an important role in determining the position or location of a point in a coordinate system.

Position Vector Visualization
Examples of position vectors from origin O to points A and B.

Characteristics of Position Vectors

Each position vector has the following characteristics:

  • Always starts from the origin O (center of coordinates)
  • Ends at a specific point in the coordinate system
  • The coordinates of the position vector are the same as the coordinates of its endpoint

Representation of Position Vectors

In general, if we have a point P with coordinates (x,y)(x, y) in a plane, then the position vector from point O to point P can be written as OP=(x,y)\overrightarrow{OP} = (x, y).

In three-dimensional space, if point P has coordinates (x,y,z)(x, y, z), then its position vector is OP=(x,y,z)\overrightarrow{OP} = (x, y, z).

In the visualization below, we use the notation OA, OB, OC, and OD to indicate position vectors from point O to specific points (A, B, C, or D).

Position Vectors in 3D Space
Examples of several position vectors in three-dimensional space.

Examples of Position Vectors

Suppose there are two points A and B in the coordinate plane:

  • Point A with coordinates (3,2)(-3, 2)
  • Point B with coordinates (7,5)(7, 5)

Then the position vectors of these two points are:

  • OA=(3,2)\overrightarrow{OA} = (-3, 2)
  • OB=(7,5)\overrightarrow{OB} = (7, 5)

Benefits of Position Vectors

Position vectors have several benefits in mathematics and its applications:

  1. Determining the location of a point in a coordinate system
  2. Serving as a basis for calculating other vectors such as displacement vectors
  3. Facilitating the solution of problems related to position and location
  4. Used in GPS technology to determine the position of a location

Relationship with Displacement Vectors

Displacement vectors can be obtained from the difference between two position vectors. If we have position vectors OA\overrightarrow{OA} and OB\overrightarrow{OB}, then the displacement vector from A to B is:

AB=OBOA\overrightarrow{AB} = \overrightarrow{OB} - \overrightarrow{OA}
Relationship Between Position Vectors and Displacement Vector
Displacement vector AB is obtained from the difference between position vectors OB and OA.

From the previous example, the displacement vector from A to B is:

AB=OBOA=(7,5)(3,2)=(7(3),52)=(10,3)\begin{align} \overrightarrow{AB} &= \overrightarrow{OB} - \overrightarrow{OA} \\ &= (7, 5) - (-3, 2) \\ &= (7-(-3), 5-2) \\ &= (10, 3) \end{align}

Therefore, to move from point A to point B, we need to move 10 units to the right and 3 units upward.