Interpolation

In some applications, a function y = f(x) is usually given at some discrete points, such as (x₀, y₀), (x₁, y₁), …, (x_{n - 1}, y_{n - 1}).

To find the value of y at the value of x, you construct the function that closely fits those data points. In the case of interpolation, a type of curve fitting, the function must fit the given data points exactly.

According to interpolation, the equation

defines x and y with the values in the following table:

x	y
-1	0.0769231
-0.6	0.18797
-0.2	0.675676
0.2	0.675676
0.6	0.18797
1	0.0769231