46: Chapter 49 No one was lying on their desk during this class.

The murmurs in Class 18 hadn't completely died down when Fang Jiming had already drawn a parabola on the coordinate axis. The lines were so clean that even Lin Xiaoxi took a second look.

Qian Duoduo opened his textbook, glanced at the dense formulas, and his earlier excitement instantly collapsed.

Qian Duoduo: (ꐦ ‵□′)

"Brother Fang, my head hurts just seeing these letters and numbers squeezed together. Can you speak human language?"

Fang Jiming didn't even turn his head; his fingers drew something else on the blackboard.

A sniper rifle.

To be precise, it was a very simple, yet instantly recognizable AWM.

The whole class went quiet.

Zhao Dazhuang was the first to react. All his sleepiness vanished, and he sprang up from his chair.

Zhao Dazhuang: (✧ ω ✧)

"Brother Fang, is that an AWM you drew?"

Fang Jiming turned around to look at him, spinning the stylus between his fingers.

"Zhao Dazhuang, I remember that besides playing Honor of Kings, you also play FPS games. Today, I'll use FPS games to ask you: if you're standing on high ground shooting at a moving target, can you aim directly at the head?"

Zhao Dazhuang's eyes lit up instantly.

"Of course not. Bullets have a parabolic trajectory, and you have to lead the shot. The further the distance, the higher you have to aim."

Fang Jiming turned and wrote a line on the blackboard.

[Bullet flight trajectory ≈ Parabolic equation (simplified model)]

"What you just said, translated into mathematical language, is the content we're learning today."

He marked a point at the muzzle of the AWM, marked a moving target point on the ground, and drew an arc from the muzzle to the target.

"After the bullet leaves the muzzle, it is affected by gravity. If we ignore air resistance, the flight trajectory can be approximated as a parabola. The equation is y equals ax squared plus bx plus c."

Fang Jiming tapped the coordinate axis on the screen.

"a determines the width of the parabola's opening, which is what you call bullet drop speed in games."

Zhao Dazhuang nodded frantically.

"b determines the offset direction of the parabola, which is the lead you need when shooting at long distances."

Zhao Dazhuang's mouth was agape.

"c is the initial height, which is how tall the building your character is standing on is."

Fang Jiming drew another scene on the screen: a three-story building with a stick figure standing on the roof holding a gun, and a stick figure running on the ground.

"Now, assume you are standing on the third floor, the building is 12 meters high, the target is moving horizontally on the ground at 5 meters per second, and the gravitational acceleration is 10."

He labeled the corresponding letters next to each piece of data.

"Calculate your aiming angle and the horizontal distance of the bullet's landing point."

The thirty-something students in the class were all stunned.

This was a math problem.

But it was about how to get a precise headshot in a game.

Zhao Dazhuang grabbed his pen and started listing equations on his draft paper, his hand moving faster than when he played games on a keyboard.

Qian Duoduo stared at the stick figures on the blackboard for five seconds, then suddenly slapped his thigh.

"Holy crap, I think I get it."

Fang Jiming: (≖ ‿ ≖)

"If you treated every math problem like calculating game trajectories, what do you think you could score?"

Qian Duoduo counted on his chubby fingers.

"At least not single digits."

Fang Jiming walked over to his desk and glanced at what was written on his draft paper.

"You swapped the positions of a and b."

"a is the opening coefficient, not the offset. Just like when you use an AWM, bullet drop and leading the shot are two different parameters. You wouldn't set your sensitivity to match your scope magnification, would you?"

Zhao Dazhuang snickered in the back.

Qian Duoduo blushed and quickly corrected it.

Fang Jiming returned to the podium and drew a second scene on the blackboard.

This time it was a soccer field, with a stick figure standing outside the penalty area, drawing the trajectory of a curved shot.

"Wang Tiezhu, do you play soccer?"

Wang Tiezhu was stunned for a moment, then nodded.

"Then tell me, why can a banana kick curve around a wall of players and fly into the goal?"

Wang Tiezhu thought about it.

"Because the ball is spinning, and there's some kind of air force."

"The Magnus effect." Fang Jiming wrote the term on the blackboard.

"But the ball's flight trajectory is essentially a parabola plus a lateral offset—which is what we learned today, plus an additional horizontal component."

He listed the formula on the screen, accompanied by a sketch of the soccer ball's flight.

Wang Tiezhu stared at the formula for a long while, then picked up his pen and copied it into his notebook.

It was the first time Wang Tiezhu had voluntarily copied down a math formula.

Fang Jiming didn't look back at him, but the corners of his mouth curled up behind the podium.

Zhang Ming raised his hand.

"Brother Fang, can you use this to calculate the release angle for a basketball three-pointer?"

Fang Jiming pointed at him.

"You go back and calculate it: the standard three-point line is 6.75 meters from the basket, the basket height is 3.05 meters, assuming a release height of 2 meters and a release speed of 8 meters per second, find the optimal release angle."

"Hand the answer to me. If you calculate it correctly, I'll add 5 points to your final math grade."

Zhang Ming's eyes lit up; he was eager to pull out a calculator right then and there.

Fang Jiming spent forty minutes explaining the entire concept of parabolic equations, from game trajectories to soccer curves, and then to basketball shots, interweaving the three scenarios. Not a single person in the class was slouching.

Su Xiaoxiao secretly raised her hand in the corner, then pulled it back.

Fang Jiming saw it.

"Su Xiaoxiao, what do you want to ask?"

Su Xiaoxiao's voice was so soft it was almost inaudible.

"Um, the trajectory of fireworks exploding in the sky, is that also a parabola?"

Fang Jiming was stunned for a moment.

"Yes."

He drew the explosion of a firework on the blackboard, labeling the equation for each spark's trajectory.

"Every spark is an independent parabola with different parameters, which is why the shapes are different."

Su Xiaoxiao looked at the firework made of mathematical formulas on the screen, the corners of her mouth curved up, and she lowered her head to draw earnestly in her notebook.

She was writing out the equations.

Lin Xiaoxi, sitting next to her, glanced at Su Xiaoxiao's notebook, then looked at the mathematical firework on the blackboard. She picked up her pencil and wrote a small line of text in the margin of her sketchbook.

y = ax² + bx + c.

It was the first time a mathematical formula had appeared on Lin Xiaoxi's sketchbook.

Outside the classroom, by the corridor window, the Physics teacher, Lao Liu, had been standing there with his chipped enamel mug for who knows how long.

He had been passing by when he heard Fang Jiming talking about ballistic trajectories. He had originally intended to go in and correct this young man, saying, "This is Physics, not Math," but the more he listened, the more something felt off.

Fang Jiming explained the parabolic equation more clearly than he had in his twenty years of teaching Physics.

And that bunch of students was actually listening.

The students of Class 18 were actually listening attentively to a math class.

Lao Liu's hand holding the teacup shook, spilling tea on the back of his hand, which made him hiss in pain. He hurriedly retreated to the office and sat down in his chair, speechless for a long time.

The English teacher, Sister Zhang, pushed up her glasses and looked at him.

"Lao Liu, why do you look so terrible? What happened in Class 18 again?"

Lao Liu opened his mouth.

"That Fang Jiming is teaching math, and while he's at it, he's covered half a semester of my Physics content."

Sister Zhang's glasses almost slid off the bridge of her nose.

"What do you mean?"

Lao Liu took a gulp of tea before he could squeeze out a sentence.

"I mean, he used ballistic trajectories to teach parabolic equations, and the whole class actually understood it. Even Zhao Dazhuang is doing problems."

Lao Liu: (ꐦ ⊙ _ ⊙)

Sister Zhang took off her glasses, wiped them, and put them back on.

"Zhao Dazhuang? That Zhao Dazhuang who sleeps in class?"

"Yes, that Zhao Dazhuang."

Sister Zhang clutched the lens cloth in her hand for a long time without letting go.

"This Fang Jiming, who exactly is he?"

Lao Liu shook his head, staring at the chip on his enamel mug.

He had been teaching for twenty years, and for the first time, he was left speechless by a young substitute teacher.