TABLE OF CONTENTS We use the notation of vectors as
or simply as A = ( A i), B = ( B i), C = ( C i) in the cartesian frame of reference. Kronecker s delta ? ij is a second-order tensor, and ? ijk is a third-order skew-symmetric tensor, which are defined by
It is useful to introduce the following vectorial differential operators,
where f( x, y, z) is a scalar function.
A scalar product of two vectors A and B is defined by
where A denotes the magnitude of A, i.e. 
, and ? is the angle between A and B.
If A is the differential operator ?, we have the definition of divergence div:
If B is the differential operator ?, then we have the definition of A grad:
A vector product of A and B is defined by
where i , j , k are unit vectors in the directions of x, y, z axes respectively, i.e. i = j = k = 1, i j = j k = k i = 0. Using the angle ? between A and B, the magnitude of A B is given by
A B
