Representingtitg conics using NURBS curves

The necessary and sufficient conditions are presented for NURBS currve s of an arbitrary degree to precisely represent circular arcs. NURBS curves of degree 2 or degree 3 representing circular arcs can be regarded as special cases of the conditons. It is studied whether two NURBS curve s of degree three are equivalent Classifications of conic section curves represented by cubic or quadratic NURBS curves are proposed