Research on Convexity of Nonsmooth Functions
Song Hu · Journal of North China Institute of Technology · 2002
Aims To solve the problems of the directional derivative of the multivariable functions. Methods We can simplify multivariable function with the help of single variable function. Results We change the directional derivative of the multivariable functions into the left and right derivative and the progressive derivative of the singlevariable functions with the help of the definition and the property of the singlevariable functions. As a result, the difficult point in the study of the infinitesimal calculus can be solved. Conclusion In the process of the study of the infinitesimal calculus, we can use the simple knowledge which has been learned to simplify the more difficult contents.