Sclar dot product

Scalar Dot Product:
The scalar product of to vectors A and B is written A . B is define
A . B = AB cos

where A and B are the Magnitude of vectors A and B and Angle between them

dot product of to vectors A and B interpretation for physical, These are brought to origin in common.
then, A.B = (A) (projection of A and B)

A.B = A (magnitude of components B in the direction A)
= A (B cos) = AB cos

Similarly     A.B = B ( A cos) = BA cos

Characteristic of scalar product:
1. since A.B = AB cos and B.A = BA cos.
in other words, scalar product is commutative.
2. The Scalar product of two mutually perpendicular vector is zero A.B = AB cos90 = 0
3. The scalar product of to parallel vectors is equal to the product of their magnitudes. Thus parallel vectors angel = 0
4. The self product of vector A is equal to square of its magnitude.