Memorandum on Notation
Vectors are denoted by letters in clarendon type, as E.
The three components of a vector E are denoted by Ex, Ey, Ez, and the magnitude of the vector is denoted by E, so that
The vector product of two vectors E and H, which is denoted by [E.H], is the vector whose components are (EyHz - EzHy, EzHx - ExHz, ExHy - EyHx). Its direction is at right angles to the direction of E and H, its magnitude is represented by twice the area of the triangle formed by them.
The scalar product of two vectors E and H is ExHx + EyHy + EzHz. It is denoted by (E.H).
The quantity is denoted by div E.
The vector whose components are
is denoted by curl E.
If V denote a scalar quantity, the vector whose components are is denoted by grad V.
The symbol ∇ is used to denote the vector operator whose components are , , .
Differentiation with respect to the time is frequently indicated by a dot placed over the symbol of the variable which is differentiated.