This online calculator uses several regression models for approximation of an unknown function given by a set of data points.

This online calculator derives the formula for the linear approximation of a function near the given point, calculates approximated value and plots both the function and its approximation on the graph

The calculator approximates a fractional number with a sum of unit fractions (a unit fraction numerator is one). The unit fraction denominator is a number which is less than the base times the base in integer non negative power.

This online calculator builds a regression model to fit a curve using the linear least squares method. If additional constraints on the approximating function are entered, the calculator uses Lagrange multipliers to find the solutions.