The following table lists an n^th order polynomial f(x) = a_n xⁿ + a_{n - 1} x^{n - 1} + , .... a₁x + a₀ and the forward difference evaluated at equally spaced values of x. The order of the polynomial is

x	f(x)	Δf	Δ2f	Δ3f
-0.4	1.7648	-0.2965	0.089	-0.03
-0.3	1.4683	-0.2075	0.059	-0.0228
-0,2	1.2608	-0.1485	0.0362	-0.0156
-0.1	1.1123	-0.1123	0.0206	-0.0084
0	1	-0.0917	0.0122	-0.0012
0.1	0.9083	-0.0795	0.011	0.006
0.2	0.8288	-0.0685	0.017	0.0132