differential
In mathematics, differentiation is a linear representation of the local rate of change of a function. The differential can approximate how the value of the function changes when the value of the function argument is changed sufficiently small. When the arguments of some functions have a slight change, the function changes can be decomposed into two parts. A part is a linear part: in a one-dimensional case, it is proportional to the amount of change in an independent variable, and can be expressed as a product that is independent of the function and the associated quantity; in the broader case it is a linear The value of the mapping is on. The other part is more advanced than the higher order, that is to say in the future will still tend to zero. When the change is small, the second part can be ignored, the amount of change in the function is about the first part, that is, the function of the differential, recorded as or. If a function has the above properties somewhere, it is said that the function is different at that point. ...