I need matlab code for this problem, this is supposed to give a graph for the chebsyshev points and one for the normally equally spaced points, any help would be great:

Observe the error of a polynomial interpolant by plotting the function E(x) = C product (x - xi), with C = 1, for

[i] {xi} nine equally spaced points in [-1; 1]
[ii] {xi} nine Chebyshev points in [-1; 1]

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Always try the help manuals.

This might help you out.

http://www.mathworks.com/access/helpdesk/help/toolbox/splines/chbpnt.html

Thanks
Matt