The second question:

The third question:

The fourth question:

The fifth question:

This part of the extended information mainly examines the knowledge points of analytic functions:

Between two variables A and B, if A has a unique value corresponding to each value of B, then A is a function of B ... From the corresponding point of view, there are two forms:

1, one-to-one, that is, a b value corresponds to an a value, and vice versa (of course, b is also a function of a at this time).

2. One-to-many means that multiple B values correspond to one A value. (At this time, one A value corresponds to multiple B values, so B is not a function of A).

There are three main ways to express functions: list; Image; Analytical formula (commonly used). Therefore, the resolution function is just an expression of the function.

Because the independent variables have different values, they are two different functions. Sometimes in the process of function writing, there will be forms of omitting the range of independent variables: for example, y = 2x-5; (4)y =√2x-5； (5)y= 1/(2x-5), then their independent variable range is the value of the independent variable that makes the expression meaningful. The independent variable range of is: x is any real number (note: this concept is discussed in the real number range by default, the same below); The range of independent variables is: x & gt=2.5; The range of the independent variable is: x≠2.5.