This function allocates space for a Chebyshev series of order n
and returns a pointer to a new
This function frees a previously allocated Chebyshev series cs.
This function computes the Chebyshev approximation cs for the function f over the range (a,b) to the previously specified order. The computation of the Chebyshev approximation is an O(n^2) process, and requires n function evaluations.