"Shabi, are you still being a wooden man and being beaten by you?"

The students in the past saw that she was an old teacher who was respectful, and no one spoke up about criticizing others, so they accepted it with an open mind. The more she thought about it, the angrier she became

At this time, high blood pressure came up, and she was dizzy, and instantly turned into an orangutan girl.

After the outbreak, the "old lady" had extraordinary combat effectiveness, grabbed a pile of chalk in one hand, overcame reason with anger, and began to attack by mistake. The most pitiful are the classmates around Lin Xiao.

Small white missiles were shooting intensively towards Lin Xiao, Lin Xiao's hand was extremely fast, Donkey Kong Bodhi kept drawing circles, and the small missiles were almost caught by him.

The "old lady" was taken aback!! this still missed.......

"I've been teaching for 30 years, and I've never seen such a bad student come to my office after class. ”

Many students gloated, Lin Xiao had just come back on the first day, and he provoked the "old lady", and he didn't know how to write dead words at all.

The old lady realized that the punishment she had just given had affected her dignified image of fairness and justice in the past.

The teacher has always had clear rewards and punishments, and if you can answer the question you just talked about and make a mistake, the teacher will no longer pursue it. But if you can't figure it out, not only will you come to my office after class, but you will also have to hand in a 20,000-word letter of repentance tomorrow, do you understand?" the old lady smiled meaningfully.

"Teacher, do you mean that as long as I solve it, there will be no problem?"

"Yes, as long as you solve it, the teacher will not punish you. ”

But I thought in my heart: If a student like you can solve it, I won't be a teacher in my life, and the whole class can go to Tsinghua University and Peking University in the college entrance examination.

Lin Xiao turned his mind and decided to make a plan.

"Teacher, this question looks very difficult, even you are stuck, if I am lucky and really solve it, will it be okay later?"

"What the teacher said just now, the students have heard it, as long as Lin Xiao can solve it, all the punishments will be canceled today. There was a mocking smile in his eyes.

"Then I'll be relieved, after all, the teacher won't lie. Lin Xiao's eyes flashed with a gleam.

He pretended to be very flustered, trembling and trembling as he walked forward, one step at a time, already frightened by the problem.

Everyone thinks that Lin Xiao will definitely not be able to solve it, and solving the problem requires not only IQ, but also courage.

All kinds of sighing voices in the audience came and went.

"The "old lady" with 30 years of teaching experience can't do it, Lin Xiao is just pretending."

"I think so, too, if he solves it, he can become a math teacher."

"We'll see him make a fool of himself."

In front of everyone's eyes, Lin Xiao stood in front of the blackboard, motionless.

After 3 minutes, he showed a very embarrassed expression, "Teacher Chen, this question is too difficult, I only have a little idea."

"Old lady" looked like a villain, and pretended to be a good person with a big tail: "Lin Xiao, don't be nervous, you can write, if you write it, the teacher will approve you to sleep when you are tired from math class in the future."

"Teacher Chen is 8 percent because he can't solve it, so he jokes with him."

"Teacher Chen, it's so humorous."

"Lin Xiao, an idiot, where can he solve it, and it's not Liu Qingqing."

At this time, the whole classroom was silent,

Lin Xiao hesitated for another 1 minute and said, "Teacher, my math foundation is too poor. If you're really lucky enough to figure it out, can you lend me a three-year-old teacher's book for a few days?"

The old lady agreed, "Yes, if you really solve it, I will promise you everything, but the premise is that you can!

Lin Xiao continued to pretend to stand and think.

"I haven't come to class for 2 years, how can I solve it".

"Does he think he's a child prodigy?"

"If he can figure it out, I'll have his last name." The gossip discussion became more intense. The old lady didn't mean to stop it at all, she just wanted to see Lin Xiao make a fool of herself, the more she mocked, the more Lin Xiao couldn't figure it out.

A minute later, Lin Xiao's sincere fear suddenly disappeared, and he quickly wrote down the entire solution on the blackboard.

"Da Da" is the sound of chalk writing, and the audience is much quieter.

"He must have scribbled".

"He must have made it up."

I saw it on the blackboard:

Step 1:

Establish the three-dimensional coordinate system O-xyz according to the figure

After that, bring in the coordinates of the point and find the coordinates of the desired vector.

Step 2:

Find the normal vector of the plane:

Letting normal vector n=(x,y,z)

Because the normal vector is perpendicular to this plane

So n is perpendicular to this plane and two intersecting lines (whose direction vectors are a, b)

Two equations can be listed: n·a=0 and n·b=0

Two equations, three unknowns

Then according to the calculation convenience

Take z (or x or y) to equal a number (e.g. 1, √ 2, etc.)

Substituting can find the coordinates of a normal vector n of the surface

After finding the n coordinates, and finally substituting the known quantity,

Finally, the length of QE is calculated to be 45.

As Lin Xiao's last word fell, the students in the audience were divided into 2 batches.

The group with better grades was dumbfounded, and sighed, "Why didn't I think of this method," and had some admiration for Lin Xiao. The classmates with bad grades unanimously thought that Lin Xiao was scribbled, how could such an idiot make it.

They looked at the "old lady" with extremely eager eyes, hoping that the "old lady" would loudly reprimand and veto Lin Xiao.

But there was no response.

Because the "old lady" her own jaw is about to fall, although she has just been stuck with the master, she has the correct answer, which is exactly the same as Lin Xiao's, that is, 45.

Lin Xiao's handwriting is strong and powerful, the steps are extremely accurate, and the method is impeccable, and he didn't even think of using this solution.

remembered that he had just promised Lin Xiao that as long as he solved this problem, any request could be met to him.

Oh my God, he wouldn't want to do that to me, I'm so shy, it's my first time." Looking at Lin Xiao's handsome and fair cheeks, the old lady fell into a girl's fantasy.

The more she thought about it, the redder her face became, if Lin Xiao could read her thoughts at this time, she would definitely vomit blood and die.

With you as you are, if I do "that" with you, I might as well just hit the wall.

After all, she has been single for 50 years, has not been married, has no children, and is still ......

One can imagine how ugly this old teacher is and how bad his personality is.

In the end, the whole class looked at the old blushing "old lady".

Lin Xiao reminded, "Teacher Chen, can you lend me all the teacher's books and all the exam papers for each semester after class?"

"It's dripping. The old lady looked at Lin Xiao affectionately.

"Do you have any other requirements, such as individual tutoring from the teacher?" The old woman deliberately buried her head down.

He continued to add, "Lin Xiao, you haven't been here for so long, and the teacher thinks you need my individual tutoring."