Inverse Problem of Approximation for a Polynomial Cubic Transformation Function for a Sensor

An inverse problem of approximation is formulated for the example of a third-degree polynomial transformation function. It is shown that in many cases the given problem is incorrect because of the violation of the uniqueness of the existing solution. An analytical solution of the problem is constructed. This solution is compared with Newton’s numerical method in order to fi nd roots that show the natural regularity of the inverse approximation problem.