Vectors are the physical quantities which have both magnitudes and directions and obey the triangle/parallelogram laws of addition and subtraction. It is specified by giving its magnitude by a number and its direction, e.g. Displacement, acceleration, velocity, momentum, force, etc. A vector is represented by a bold face type and also by an arrow placed over a letter, i.e.
`F, a, b` or `vecF,veca,vecb`.
The length of the line gives the magnitude and the arrowhead gives the direction.
The point P is called head or terminal point and point 0 is called tail or initial point of the vector OP.
`| lambda A| = lambda |A|`, if
Options:
(a) `lambda > 0`
(b) `lambda < 0`
(c) `lambda=0`
(d) `lambda!=0`