  In this paper we shall show that the metrics are equivalent which obtained by
Feng and Mao in [[1], Y. Feng and W. Mao, Equivalence of Cone Metric spaces and
Metric Spaces, Fixed Point Theory, 11(2)(2010), 259-264.] and Du in [[2],
Wei-Shih Du, A Note on Cone Metric Fixed Point Theory and its equivalence,
Nonlinear Analysis, 72 2259-2261 (2010)]. Also in the sequel we calculate some
examples by one of the metrics.
