Love lasts a lifetime

He Yu put three questions on the blackboard and asked three students to come up and do one question each.

In just a few minutes, the students who came to do the questions quickly completed the questions asked by He Yu.

The students below also finished it quickly.

He Yu asked:"Is there any of the students below who can't do it? Please raise your hand!""

…….

He Yu saw that no one raised their hands.

He asked the students in the front and back rows to exchange inspections with each other.

After the inspection, he asked:"Have any mistakes been found? If so, please raise your hand!"

He Yu looked and saw that no one raised their hands.

He said,"Ask the students below to pair up. Are your answers the same as those of the three students above?"

The students below shouted in unison,"They are all the same!"

He Yu continued,"Then When doing homework in the future, the students will do what Li Juan said, so that they are not constrained by the absolute value sign.

However, the slopes of the two straight lines must be calculated in order to compare their sizes.

Subtract the one with the larger slope The slope is small, so the positive value of tanθ can be calculated"

TodayThat’s it for learning the formula for the angle between two straight lines.

Colleagues, if you have any questions that are unclear, please raise your hands?"

A female classmate raised her hands and stood up and said,"Teacher!

If we don't use formulas with absolute value symbols during the exam, will the teacher who corrects the paper deduct my points?"

"Let the students answer this question you asked!"

A male classmate stood up and said,"Are you still doubting what Li Juan said?

It shows that you yourself look down on your female classmates!

You are still stuck in a rut and blindly worship experts.

Teacher He is not encouraging us not to be slaves to teaching materials, but to be masters over knowledge!

I never thought that Li Juan could boldly propose this approach.

We only believe in the truth and do not trust experts.

You should boldly follow this method during the exam. The absolute value symbol is used to calculate the positive value of tanθ. Without the absolute value symbol, the positive value of tanθ can be calculated directly.

If anyone dares to deduct your points, our whole class will go to him to argue.

If anyone dares to deduct your points, it can only mean that he is a follower.

Do your classmates agree with my point of view?"

The whole class clapped their hands and shouted in unison:"That's right!

We must learn from Li Juan that she dares to challenge the experts who write textbooks!

At this time, He Yu said:"Thank you, students!"

Although it is simply to remove the absolute value sign to calculate the positive value of tanθ.

But it shows that the students have the courage to break the rules and propose more scientific and simple calculation methods, and it shows that everyone dares to emancipate their minds. Always be innovative, this is a valuable spirit in your learning and growth process. That concludes today's lesson. get out of class is over!

At this time, the students all stood up and shouted:"Hello, teacher!"

Thank you teacher for giving us a wonderful math class!"

The teachers who came to listen to the class also stood up together with the classmates!

But there were still a few who sat still. They were still showing off their seniority!

After the open class, many teachers were deeply moved and talked about it.

Originally, there was a meeting with all the people who came to listen to the class. However, at the request of several seniors, we first convened a symposium with some students.

The leaders of the Education Bureau had already guessed why they wanted to do this. The leaders of the Education Bureau asked

Principal Yin to Go and inform a dozen students who spoke actively to stay in the classroom and ask He Yu to get out of the way.

Really; the students are so courageous that they dare to argue with the teacher who corrected the paper.

Without He Yu's support, they would dare to do this Say?