With such a Bole as black-faced carbon, Fang Chao, a thousand-mile horse, fully exerted the level of strength he should have.

Black Carbon has a deterrent effect that allows him to learn mathematics more efficiently, but every time he sees Black Carbon hair, Fang Chao has the idea of relaxing first.

"You can't keep staring at other people's heads, otherwise what kind of system will it become......"

On a weekend, when Zheng Yihang took a week of math classes, Fang Chao finally completed all the math lessons in high school, which took more than a month, plus a few days of summer vacation.

In the evening, Fang Chao called Black Carbon.

"Teacher Lin, I've learned all the math in high school, and you can come up with some exam questions for me to do this week."

"Okay, you kid is awesome, wait to see how I deal with you, and see if you kid dares to hand me in early!"

Fang Chao thought of the way he looked like thunder every time he handed in the paper early, and the corners of his mouth couldn't help but rise slightly, black-faced carbon, you are obviously almost fifty years old, how can you still be angry as a child? There's no such thing as a mature adult at all, so people are worried about you......

There is reincarnation in the way of heaven, who is spared by the sky!

Fang Chao, who had never returned on the road of pretending to be forced, finally encountered the most difficult problem in history.

In the third week of special training, the black face carbon threw Fang Chao a math problem.

The title is sauce purple.

In the planar Cartesian coordinate system x0y, let AB be the chord of the parabola y²=4x crossing point F(1,0), and △A0B's circumscribed circular parabola at the point P (different from the points 0, A, B). If BF divides ∠APB equally, find all possible values of PF丨.

"I'm so hard...... In vain, I boast that I don't have any math problems that can stump me...... But now, I can't even solve a math problem with black carbon...... I've become a salted fish......"

Why is this question so difficult...... I'm so miserable, but I don't believe I can't handle it, black-faced carbon, you wait, you can't trouble me, one day I will turn over your five finger mountain, I believe, I can come out soon. ”

"I'm such a monkey, who can hold me down...... Hahahaha. ”

"I want this day, I can't cover my eyes anymore, I want this land, I can't bury my heart anymore, I want all living beings to understand my intentions, and I want all the Buddhas to disappear!"

“……”

"No, no, it's still too difficult, just some simple ideas, if it goes on like this, I'll go crazy......"

Fang Chao was almost on the verge of collapse, looking at Fang Chao with such a helpless appearance, especially grasping his scalp with his hands, he could feel that dozens of hairs might fall out at this moment, he was very happy.

You kid, can finally encounter math problems that you can't solve?

I thought you were so strong, I thought you were invincible in the world, scared me to death!

After two weeks of special training, Fang Chao was able to easily deal with the questions of the black carbon, although it took a little more time, but in the end they were slowly solved, with such a talent, it was not difficult to achieve certain results in the national decision, but he hoped that Fang Chao was comprehensive, so he took out some more complex question types, so that Fang Chao would continue to transform.

However, Fang Chao's appearance also made him a little worried, would he use more force and directly make this kid decadent?

"Need me to give you some tips?"

"Teacher Lin, let me do it myself, give me another ten minutes!"

"Oh, ten minutes is fine? Interesting, okay, then let me see what answer you can give me in ten minutes......"

The current Fang Chao is indeed the same as Sun Monkey, but the Five Finger Mountain is really powerful, suppress him, in terms of his Taoism, he has not completely become a Buddha, he has not set foot in the fight to defeat the Buddha, he cannot fight with the sky, under this Five Finger Mountain, he can only be a monkey with a rebellious heart but can never turn over the Five Finger Mountain.

Ten minutes later, Lin Seng came again.

Fang Wukong's scalp exploded, but he had to come to Lin Seng for help, only Lin Seng could help him get out of the sea of suffering.

"Teacher Lin, please, please save me, what should I do with this question?"

Seeing that Fang Chao was indeed on the verge of collapse, the black face carbon was very happy in his heart, and decided to help Fang Wukong get out of the Five Finger Mountain, he climbed the Five Finger Mountain, and silently recited the incantation on the Five Finger Mountain: Veda bisect angle, Fermat absolute value......

it!

it!!

Groove !!

Fang Wukong broke away from the Five Fingers Mountain of Rulai, the whole person suddenly became enlightened and energetic, and instantly understood, it turned out to be like this, he actually fell into such a demon obstacle for so long, it was really, he was demonic.

It wasn't supposed to be like that, and he was stuck on such a question for nearly an hour.

"Goblin, watch me uncover your true nature!"

So Fang Chao began to put pen to paper.

Solution: Let A{y1²/4,y1},B{y2²/4,y2},C{y3²/4,y3} be known from the condition that y1, y2, and y3 are unequal and non-zero, and the equation for the straight line AB is x=ty+1 and the parabolic equation is combined to obtain y²--4ty=0, and x=y²/4 is combined to obtain y4/16+{1+d/4}y²+ey=0, and the quadratic equation has four different real roots, y=y1, y2, y3, 0, and y1+y2+ according to Veda's theoremy3+0=0, so y3=-(y1+y2).

"Hmph, it's very simple, I actually had to think about it for so long just now, I'm not happy......"

Soon, Fang Chao continued to answer.

Since PF bisects ∠APB, it is known by the angular bisector theorem, 丨PA丨/丨PB丨=丨FA丨/丨FB丨=丨y1丨/丨y2丨

……

……

（y1²+y2²）²=192+（y1y2）²=208

……

Because y1²+y2²=4√13>8=丨2y1y2丨

……

丨PF丨=√13-1.

“perfect！！”

Fang Chao solved a math problem and was very happy.

[System prompt: You have been instructed by a famous teacher, successfully solved a moderately difficult math problem, and obtained 300 points for Xueba, please make persistent efforts on the road of learning and work hard. 】

So far, since the black face carbon conducted special training on him, the improvement speed of Fang Chao's Xueba points has been accelerated several times, and now, his Xueba's total points balance is 10,326 points.

The total points of Xueba exceeded 10,000 again!

And his comprehension of mathematics is getting deeper and deeper, and all the knowledge of high school mathematics is in his mind.

The days passed unconsciously, and the day of the rematch of the National High School Math League was getting closer and closer.

The selection of this year's CMO National Finals was finally decided at Jinling University.

"Jinling University? It is said that there is a senior who is particularly powerful......"