21. To each of the eight literals in this formula we assign one real variable in an eight-dimensional Euclidean space. 22. This means that it is not worthy to explicitly define the domain of a function of a real variable . 23. This means that it is not worthy to explicitly define the domain of a function of several real variables . 24. We can proceed to make social choices based on real variables , and thereby address actual position, and access to advantage. 25. Integration of such functions can be extended to functions of more than one real variable ; this extension is multivariable calculus. 26. Generally, it extends the idea of the derivative from real-valued functions of one real variable to functions on Banach spaces. 27. For simplicity, in this article a real-valued function of several real variables will be simply called a "'function " '. 28. For simplicity, in this article a real-valued function of a real variable will be simply called a "'function " '. 29. The books cover mathematical analysis of function of one real variable, functions of many real variables and of complex functions. 30. The books cover mathematical analysis of function of one real variable , functions of many real variables and of complex functions.
