Vector Algebra

The quantity which involves only one value, i.e. magnitude, is called a scalar quantity. For example: time, mass, distance, energy, etc. The quantity which has both magnitude and a direction is called a vector quantity. For example: force, momentum, acceleration, etc. A line with a direction is called a directed line. Let   be a directed line along direction B.

Here,

The length of the line segment AB represents the magnitude of the above directed line. It is denoted by  or or a. represents the vector in the direction towards point B. Therefore, the vector represented in the above figure is . It can also be denoted by. The point A from where the vector  starts is called its initial point and the point B where the vector  ends is called its terminal point. …