  Chebyshev coefficients of a coordinate representation can be used to form the
corresponding velocity representation. One way is to directly apply them to the
derivatives of Chebyshev polynomials, another is to compute from them the
Chebyshev coefficients of the velocity representation. The advantages of the
latter over the former ways are illustrated. Also, the approach of generating
Chebyshev coefficients developed by Newhall (1989) is extended such that
coordinate, velocity and acceleration are consistently treated. The resulting
representations are all continuous.
