Antarctic or subtraction or subtraction or internalization is a branch of mathematics that deals with the rate of change of one sign relative to another. That is to say, the main purpose of the internal calculation is to determine the rate of change of two increasing or decreasing quantities , which have a functional relationship , relative to each other and its significance. For a real function of a real variable , the interpolation of that function at any point is equal to the tangent of the graph. The method of determining the endogenous or insulating coefficient or derivative of a function is called endocallation.