Does that mean it's not fixed? , the number that can be changed. Variables are represented by non-numeric symbols, usually in Latin letters. Variable is the antonym of constant. The purpose of variables is to describe instructions in a general way. What if you can only use the real thing? This directive can only be used under certain circumstances. Variables can be used as a specific. The holder of any item "; The answer given by Interactive Encyclopedia is this: variables are the collective name of independent variables and dependent variables. Any system (or model) is composed of various variables. When analyzing the system (or model), we choose to study the influence of some variables on other variables. The selected variable is called independent variable, and the affected quantity is called dependent variable. Systems and models can be as simple as binary functions or as complex as the whole society. From this, we can clearly see that for mathematics, these two sets of encyclopedias are talking about "variables" and "digressions", which are beside the point.
Generally speaking, making a paper book into a so-called "photocopying" electronic version cannot be directly played on a small screen terminal device. Therefore, it is necessary
J Kessler's Basic Calculus has made great efforts in adaptation, retaining the basic characteristics of the original (rigorous and meticulous).
And turn it into a series of pocket e-books. By then, students in China will be able to surf the Internet easily, no matter when and where they use any reading equipment. As long as they open their pocket e-books, they will "open them profitably" or "review the past and learn something new". By then, the Internet will surely become an important means to spread modern mathematical knowledge. By then, the infinite teenager will smoothly enter the reader's "skull". By then, I should really retire.