The math.h cos from the article counterexample is pretty trivial, so can you give an example? I doubt linear interpolation between the 8 values is enough, but c

The math.h cos from the article counterexample is pretty trivial, so can you give an example? I doubt linear interpolation between the 8 values is enough, but cubic probably would be. This would also be close to e.g. 8 third order taylor approximations of the function, and a comparison would be interesting.