def lagrange_polynomial(x, xs, ys):
"""
- Return the Lagrange form of the interpolation polynomial in `x` of
+ Return the Lagrange form of the interpolating polynomial in `x`
at the points (xs[k], ys[k]).
INPUT:
We try something entirely symbolic::
- sage: f = function('f', x)
+ sage: f = function('f')(x)
sage: divided_difference([x], [f(x=x)])
f(x)
sage: x1,x2 = SR.var('x1,x2')