I was trying to get teh divided differences of a list of points, then I had written
divided_difference((0,1), (1,4.5), (3,14.5), (5,28.5), (6,37))
but when I tried to execute it the notebook spit out
``` NameError Traceback (most recent call last) <ipython-input-1-7581bf64e41a> in <module>() ----> 1 divided_difference((Integer(0),Integer(1)), (Integer(1),RealNumber('4.5')), (Integer(3),RealNumber('14.5')), (Integer(5),RealNumber('28.5')), (Integer(6),Integer(37)))
NameError: name 'divided_difference' is not defined ```
However the function divided_difference
appear in the manual of SAGE related to polynomials. What Im doing wrong?