Chapter 35 I, Auxiliary, Thief Six

The next day, in order to thank Sister Chen who introduced this part-time job to him, Lu Zhou decided to invite her to dinner.

However, on the issue of whether to eat yellow braised chicken or KFC, he was entangled again.

So he asked another living person in the dormitory, Liu Rui, for his opinion.

Liu Rui, who was in the dark with netizens, was sent back to the spring by the opposite side. At the moment, he was troubled and did not listen to Lu Zhou's question carefully, and replied casually without looking back: "Spicy, cheap and cheap. Affordable!"

Then……

Lu Zhou really asked.

On the snack street at the entrance of the school, at the entrance of Shancheng Malatang, Chen Yushan with a single ponytail sat opposite Lu Zhou, her tongue sticking out.

Although tears were about to come out, Chen Yushan still held on, and asked while eating, "How is it? Is my sister's math still going to be saved?"

Is it that spicy?

Lu Zhou threw a fish ball in his mouth in confusion, and said while chewing: "There is still help... Probably? In short, I will try my best."

"Then I'll leave it to you, my sister... In fact, when I was in junior high school, my grades in science were very good, but later... ah ah ah, it's killing me."

Lu Zhou silently handed her a glass of water and asked, "Later?"

After drinking the water in one gulp, Chen Yushan stuck out her tongue cutely, and continued with a slow sigh: "Later... there was a problem with my aunt and uncle's relationship, and the two were fighting for custody of Mengqi. I don't know the specific circumstances. Clearly, in short, now Meng Qi is temporarily with my aunt."

Lu Zhou nodded silently and said nothing.

He doesn't really want to care about other people's private affairs. In a sense, he is a very selfish person.

After eating the Mala Tang, Lu Zhou took Sister Chen back to the dormitory, and then turned to the direction of the library. .

On his way to the library, he received two emails.

An email is from Mr. Liu, feedback on that data modeling assignment.

Another email is a reply from the journal "Modern Communication and Geographic Information Technology", indicating that the manuscript fee has been credited to his bank card account. One article is 150 yuan, a total of 1,350 yuan, please pay attention to check it.

"..."

Nine SCI only has so much money, and it is better to make a poached egg than to build a missile...

Lu Zhou couldn't help feeling emotional.

But more than 1,000 yuan is not a lot. Counting the 3,000 yuan he earned as a tutor yesterday, and now he has more than 7,000 yuan in his card, it must be enough to pay tuition.

Originally, he planned to delay it first and make it up at one time before graduation, but now it seems that there is no need.

In the next few days, Lu Zhou's life was very regular. On Mondays, Wednesdays and Fridays, he stayed up late to read books, and Tuesdays and Thursdays were used to consolidate his studies, while previewing courses in other disciplines such as information technology, electronic engineering, biology, and chemistry. In addition, he did not fall behind in the practice of mathematical modeling.

Sometimes he really feels that if he can really maintain this good study habit, even without systematic help, he will become a scholar sooner or later.

But with the help of the system, this process is accelerated.

And it's like plugging in a rocket...

On Saturday, Lu Zhou, as usual, went to Ms. Yang's house to tutor Han Mengqi in mathematics.

Maybe it was because of the accident last time, or maybe it was some kind of agreement between the mother and daughter. This time, Ms. Yang didn't lock the door before going to work. She just told Lu Zhou to take good care of her daughter.

Watching her mother go out the door blankly, Han Mengqi looked at Lu Zhou: "Then, let's start."

After she finished speaking, she turned around and went back to her room.

Following Han Mengqi's footsteps into the room, Lu Zhou unexpectedly discovered that she had not seen her for a week, but this time she tidied up the room.

Without any extra communication, Han Mengqi spread the book on the table, turned to the folded page, and looked at Lu Zhou.

"According to the outline you gave me, I have seen Analytic Geometry, which is required for the second course... and then?"

"Then?" Lu Zhou raised his eyebrows and asked with a smile, "What did you say you didn't understand?"

"There's nothing I don't understand, it feels quite simple." Han Mengqi raised her head and said impatiently, "Then what?"

"Then I will test you," Lu Zhou took an A4 piece of paper from the side and wrote on it with a pen.

[In the Cartesian coordinate system xoy, the left and right foci of the ellipse C1: x/a+y/b=1 (a>b>0) are F1 and F2 respectively. Among them, F2 is also the focus of parabola C2: y=4x, point M is the intersection of C1 and C2 in the first quadrant, and |MF2|=5/3. Find the equation for C1. 】

After writing this question, Lu Zhou made a gesture of invitation.

Han Mengqi's eyebrows twitched slightly. She said something big just now. She didn't expect Lu Zhou to test her on the spot.

Gritting her teeth, she picked up the pen and thought for a long time on the scratch paper.

As a result, ten minutes passed, and only the first step was solved.

which is--

[From C2: y=4x, F2 (1, 0). 】

After waiting for about ten minutes, Lu Zhou looked at his watch, smiled and said, "In the college entrance examination, you are only allowed to think on one question for ten minutes at most. Now, you can only get this question at most. Three points."

"Hmm..." Han Mengqi gritted her teeth and looked unconvinced. However, problem solving is like this. Sometimes the more urgent you are, the more difficult it will be to solve it.

Lu Zhou smiled, turned out a paper from the pile of materials next to him, pointed to the position of the penultimate question, and continued: "And the most important thing is that this question is on this paper. Missed."

"...You bullied me." Han Mengqi dropped the pen and glared at Lu Zhou angrily, "I know I'm stupid."

"I'm just teaching you, and I've never said you're stupid. On the contrary, I'm very optimistic about your intelligence, so please don't belittle yourself." Lu Zhou picked up the pen she dropped and wrote the rest on the A4 piece of paper. "The key to this kind of question is to determine the value of M, so the second step must be to set M (x1, y1), and according to |MF2|=5/3, and M2 on the parabola C2, these two questions stem Solve the conditions..."

"Our second goal is to find the semi-focal length of the ellipse C1, solve this step, and the rest of the problem becomes a problem of understanding the system of equations."

Lu Zhou wrote down the key to each step on the paper, and clarified the idea of ​​solving the problem.

At first, Han Mengqi looked impatient, but then her eyes became more serious when she stared at the paper.

In the end, a trace of enlightenment appeared on her face.

Her little mouth moved slightly, and Han Mengqi, who was staring at the scratch paper intently, frowned and nodded thoughtfully, "So that's how it is..."

"Your teacher must have said it, but you haven't heard it at all."

"Our teacher... is not as detailed as you." Han Mengqi reluctantly said sophistry.

Lu Zhou was happy: "You might as well tell your math teacher this, let's see if we can make him mad."

Han Mengqi's teeth were itching with anger, but she couldn't do anything about him, so she snorted.

"No wonder my sister said you were mean..."

Lu Zhou: ? ? ?

Is someone talking bad about me behind my back?

I can't pretend I didn't hear that.

Lu Zhou coughed and disconnected the topic. He picked up the pen and said, "This question is a typical intersection point and ellipse equation problem. I believe that next time you encounter this type of question, you can get at least half of the points. ."

"Half the points left?" Han Mengqi asked, tilting her head.

"Half of the points are on the second question. This kind of question is usually examined in conjunction with the vector question in the college entrance examination, so there is usually a second question..."

While speaking, Lu Zhou continued to write after the question.

[The point N on the plane satisfies the vector MN=vector MF1+vector MF2, the straight line l∥MN, and C1 intersects the two points A and B, if the vector OA*OB=0, find the equation of the straight line l. 】

The moment she saw the title, Han Mengqi was completely stunned and looked at Lu Zhou helplessly.

However, Lu Zhou did not look at her, but sat beside the bed, picked up the exercise book beside him, and looked for the next example.

"You try to do it first. If you can't do it, I will teach you. It takes fifteen minutes. Let's start."

Worse than the first question, this time Han Mengqi only wrote one solution, and none of the rest was correct.

I don't know if it's because of having a younger sister who is about the same age, Lu Zhou didn't feel impatient, and didn't ridicule her for another "send question", but patiently explained to her the idea and process of solving the problem .

Looking at the steps on the scratch paper, Han Mengqi widened her eyes and whispered, "It's amazing..."

"My learning process is to keep summarizing and summarizing experience from mistakes. I hope you can find out the questions that you usually don't know. It is best to copy them in the notebook by yourself, and then I will explain it to you every week," Lu Zhou will Bi returned it to Han Mengqi, and said casually, "The wrong question is necessary to learn mathematics, and even all science subjects. If you want to learn science well, you must prepare. Just like ADCs go out with Dolan, assistants need to show eyes, they are all basic. operate."

Han Mengqi's eyes lit up, and she immediately became interested, and interjected: "You also play lu and lu? Which district? My nanny is thief 6!"

"……blackberries."

"I added you as a friend! Give me your Q number... ouch!"

Lu Zhou reached out and tapped on her forehead. Looking at her covering her forehead, he said angrily, "I'm still playing games, wait until you get 100 points in the math test this month!"