A counterexample of the construction of \(C^ 1\)-rational finite element due to Wachspress (Q1179390)

The authors, following the construction demonstrated by \textit{E. L. Wachspress} [ibid. 22, No. 3, 11-16 (1991; reviewed below)] prove that the interpolants corresponding to two adjacent triangular elements for the approximation of degree two, with a special choice of the triangulation of the planar region, have not \(C^ 0\)-continuity.