# Vector Solutions, Shortcuts, Formulas

**Vector Video Lecture - Page 9**

**Some Basic Concept of Vector:** Let *l* be any straight line in plane or three dimensional space. This line can be given two directions by means of arrowheads. A line with one of these directions prescribed is called a directed line * {Fig 10.1 (i), (ii)}*. Now observe that if we restrict the line l to the line segment AB, then a magnitude is prescribed on the line l with one of the two directions, so that we obtain a directed line segment

*. Thus, a directed line segment has magnitude as well as direction.*

**{Fig 10.1(iii)}****Definition:** A quantity that has magnitude as well as direction is called a vector .

Notice:That a directed line segment is a vector fig, denoted by as or simply as , and read a ‘ vector ’ or ‘vector ’.{10.1(iii)}

The point A from where the vector ’ starts is called its initial point , and the point B where it ends is called its terminal point. The distance between initial and terminal points of a vector is called the magnitude (or length) of the vector, denoted as , or a .The arrow indicates the direction of the vector.