January 1976
In this paper a formalism is developed that enables one to write down by inspection the matrix which represents the transformation between two coordinate systems, one of which is rotated by an angle theta about an arbitrary axis. Only the direction cosines of the rotation axis and theta need be known. it is pointed out that this transformation is not discussed in the usual treatments of classical mechanics.
Formalism for the Rotational Matrix of Rotations About an Arbitrary Axis