1, given plane a, straight line L 1, L2. Then two straight lines on the plane are parallel or coincident, that is,

L 1 belongs to plane a, L2 belongs to plane a, and L 1 intersection L2 belongs to an empty set, which is a representation of a set.

I can't type such words. Since you asked this question, I think you already know their symbols.

Coincidence L 1 belongs to plane a, L2 belongs to plane a, and intersection L 1 L2 belongs to all real numbers.

2. F in function f(x) is indefinite. You can use whatever you want, as long as it is English letters, regardless of size.

Write it. There is no necessary connection between those letters. As long as it is in the form of (x), it is a function.

3. First of all, every element in one set you mentioned corresponds to another (but

The only element in a set, you know, these two sets are continuous and can't be mutual.

In other words, every element in the so-called set is the domain of the function, which is where X is located.

There are various ranges of values. The other (which can be

Set refers to the value corresponding to x in the definition domain, which satisfies both many-to-one and one-to-one.

A y has many x's or only one.

Y=0, x∈R For it, X is the domain and Y is the range, that is, any value of X is 0.

So the image of this function is the x axis, and you can also think about the image of X=0, hehe, it is not a letter.

Oh, think about it. If you don't know, please leave me a message///

4. You are so talented. Later, I met this problem on the final exam paper, and it took me half an hour to solve it completely.

Later, I learned that this is called tick function. Don't look at ddxuzheng's picture, it's not quite right. Leave me a message and I'll show you the detailed explanation. PS, it would be easy to know the derivative in calculus. Whether it's any letter,

A few images can be roughly drawn.

5, which one it writes is a judgment, because when you are given a function and want to solve its range and other problems, you always make y equal to 0 first to see if there is a value of X. If there is no value of X, congratulations, this function does not exist. If y = 0 has a value of x, you should use some methods that the teacher talked about in class to solve it. What you haven't finished writing should be factorization, and the most troublesome thing is to calculate delta.

6, don't listen to ddxuzheng, he is wrong again, because the denominator △ cross is less than 0, and his value is greater than 0. As for the inequality you want to ask, it holds for any x∈R, ∴△ = [-(a+2)] 2- 16 < 0.

Because for a fractional function, its domain is the value of x calculated by making the denominator not equal to 0.

This part is over, because the denominator of your y = (x 2+ax-2)/(x 2-x+1) is always greater than zero, so his domains are all real numbers. When you do this, x 2-(2+a) x+4 >; 0, if you want to make the constant on the left greater than zero, it is equivalent to making the function y = x 2-(2+a) x+4 always above the x axis, and the upward opening can only be △ less than zero.

If you don't know much in the future, ask the teacher and don't ask your classmates, because often when you ask the next question related to this, he is wrong, and you don't know when you are wrong, and he doesn't know, which will hurt many people. After all, all the students in a class are at the same level. So unless it is a very simple question, most of them are asked by the teacher. High school is different from junior high school. Junior high school teachers are avoiding you, while senior high school teachers are expecting you. ! ! ! ! ! ! !