Rekindle 2003

Chapter 346: What is the function of a function?

In terms of age and seniority, Qing Yun is the junior, and they can clean up at will. This is a kind of closeness like family.

But in terms of status in the world, although Qing Yun is far inferior to them at the moment, as the actual controller of a large group, he is qualified to sit and discuss with them.

This is a bit uncomfortable.

The most important thing is that the topic of chat is difficult to master.

In the past, when I talked about career and work with Qing Yun, they could give me any advice.

And now...the three brothers of the Qin family are not fools. If they point fingers at Qing Yun at this time, let alone Qing Yun, their youngest brother will stand up and protest.

This is purely to cause trouble for my niece.

Fortunately, there are two weird twins in the living room.

"Brother-in-law, tell us about functions quickly. We are all going to be autistic because of high school math."

After that, the two twin beauties came to drag Qing Yun's arms.

When we talked about the topic last time, the two girls admired this brother-in-law who had not yet met him. Now that they encountered difficulties, they naturally sought help quickly.

Qing Yun blinked, and happily came to the yard under the urging of the Qin brothers.

Mainly, he didn't know what to talk to them about.

There is a generation gap.

As for the two little beauties, there is no gap.

"Brother-in-law, can you help us sort out the functions? This f(X) makes me want to give up mathematics!"

Qin Shiyue pouted her little mouth, and her immature face was full of unhappiness.

People are more mad than people.

Originally they thought they were just a little behind their sister Qin Manman in math, but after they started previewing high school content, they discovered that the difference was not 01:30.

Huating is the pioneer area of ​​many changes in China.

Unfortunately, so is education.

Qin Shiyue and Qin Shiwan happened to meet the pilot of "two exams and one exam" for the graduation exam and the entrance exam, and the difficulty of the high school entrance examination questions dropped dramatically.

This kind of change is to eliminate side questions, difficult questions, and weird questions, and focus on examining the basics.

The intention is good, but it can also cause misunderstandings.

In fact, there is a gap between a perfect score and a perfect score.

Just like what Qin Manman said to Qingyun back then, "We are tied in mathematics because the full score is only 150 points."

In high school mathematics, the sudden f(x) gave the twin beauties who were overflowing with confidence a blow.

"There is obviously y and x, why is it f(x) again! It's so annoying!"

While listening, Qing Yun suppressed a laugh.

This f(x) is actually the first difficulty that many students encounter after entering high school.

Because the textbook doesn't explain it clearly at all, it just seems to appear out of thin air. At this time, it all depends on the teacher's level.But unfortunately, many teachers have not fundamentally understood or realized that this is the first problem that makes functions appear confusing.

As for Qin Shiwan and Qin Shiyue, they were studying on their own and were naturally confused.

Qing Yun smiled and asked the two of them to take out pen and paper, "Don't worry, listen to me, I can explain it to you in a few minutes. Don't worry, it's not difficult to understand at all."

After that, he asked the two women to write an equation on paper.

"The first point to make it clear is, 'Function equals rule.' You should engrav these six words in my mind.

All functions are based on the rules of their expression.

For example, the linear function y=f(x)=2x+3 means 'give an x, according to what rules to get a y, the rule is to first multiply x by 2 and then add 3 to the result', you can understand this sentence No? "

The two beauties thought for a while and nodded. After Qing Yun confirmed that they understood, he continued, "Look, f is the code name of the rule. f(x) means to be under the rule represented by f." , to process x, you see, the parentheses firmly frame x, which means that x is not allowed to escape its control.

y=f(x) means that the processing result is given to y.

Now, let’s understand, y=f(x)=2x^2-5x+7.

If there is only the first half of y=f(x), we only know that x must be calculated under certain rules, but we don't know how to calculate it. With the second half, we know what the rules are.What is it? "

The twin beauties nodded obediently and answered in unison, "Just follow the known rules and give me an x ​​to calculate a result, and then let y equal this result."

"So, we use f(x) to represent any function. It is just a function anyway. The specific rules have not been written out yet. As for y=f(x), it just means that the result of this function is represented by y.

Then what about m=(t)? "

"It means that t is calculated under certain rules, and the result of the calculation is given to m. Do you understand the essence? In fact, they are just paper tigers."

Qin Shiwan pouted when she heard the words, but Qin Shiyue pouted, "Brother-in-law, you said it easily. Now I find more and more that mathematics is like, you can understand the concepts as soon as you talk about them, and you can't understand them as soon as you solve the problems." .”

Qing Yun shrugged, "That means you don't understand the concept at all."

Looking at the two beauties showing their teeth and claws, Qing Yun smiled and said, "Then let me ask you, what is a function? What is a letter? Why is it called a letter?"

Qin Shiwan was about to endorse, but was completely overwhelmed by Qing Yun's next two questions.

"Let me tell you my opinion. Letter means box. This box is like a TV. The input model is processed and the result is a picture. Between the signal and the picture, there are established operating rules inside..."

"NND, no teacher ever told me this back then. If I had met a teacher like you, I would have been able to pass the Qingbei exam!" Qin Xiangyu, who quietly slipped out and was listening secretly next to him, suddenly sighed with emotion.

Qing Yun smiled and handed the brother-in-law a cigarette, "The symbol f(x) is so natural to textbook writers and teachers who are familiar with functions, as if 1+1 equals 2, no explanation is needed. It’s hard to explain, but for students who have just entered high school, it is a different experience.

So, in fact, there is something wrong with our current education, not just schools. There is something wrong with the methods and methods of education. Those who teach take it too much for granted, and those who learn naturally cannot listen.

The importance of empathy in education and teaching is to figure out what the given thing means to the students, rather than just focusing on what it is. "

Before Qin Xiangyu said anything, Qin Tianshan, who came out to smoke and care about the study status of his precious girls, suddenly stopped.

Qin Tiansheng, who followed him out, looked at Qing Yun in the yard with a strange expression, "Xiao Qing, there is something in your words."

Obviously, this kid must have seen them. When they walked out of the living room, his voice was obviously louder.

Qing Yun chuckled twice, "Third uncle, if you don't mind, ask Brother Xiangyu to help me."

Qin Tiansheng was stunned for a while, and then he laughed in relief, "If you don't dislike your brother Xiangyu, you can just teach him."

(End of this chapter)