Rotational Equations of the Plane Parallel Motion for the Rigid Body

On the discussion of how to establish rotational equations when taking the dynamical point as the base, the present paper proposes the condition on which rotational equations built on the basis of non center of mass dynamical point would keep with rotational equations about a fixed axis of the rigid body. And also argues, taking the instantaneous center as an example, that it is much easier to find the solution to the plane parallel motion of the rigid body by selecting the instantaneous center as its base than the center of mass on the special condition.