"Common trigonometric functions include sine, cosine, and tangent functions. In other disciplines such as nautical science, surveying, engineering, and so on, we also use other trigonometric functions such as cotangent, secant, cosecant, versed sine, versed cosine, half versed sine, half versed cosine, etc."
"Additionally, using trigonometric functions as templates, we can define a similar class of functions called hyperbolic functions. Common hyperbolic functions are also referred to as hyperbolic sine, hyperbolic cosine, and so on."
Bi Xia pointed at the right triangle, "In a right triangle, when the three points A, B, and C on the plane are connected, AB, AC, and BC form a right triangle, with ∠ACB being the right angle. For ∠BAC, the opposite side a=BC, hypotenuse c=AB, and the adjacent side b=AC."
"Therefore, sinA=a/c which is the ratio of the opposite side to the hypotenuse for angle A, cosA=b/c which is the ratio of the adjacent side to the hypotenuse for angle A, tanA=a/b which is the ratio of the opposite side to the adjacent side for angle A." Thɪs chapter is updated by novelFirｅ.net
On the platform, the young boy seriously explained the knowledge points, marking each key point particularly. Below the platform, every student had abandoned their previous confused looks, each holding a notebook and jotting down every key point that Bi Xia emphasized.
"Now, take out last week’s math exam paper. The fifth question in the multiple-choice section is a typical problem that utilizes this formula. Those who got this question wrong should take out your correction book and organize it afterwards."
Xu Renfei looked at Bi Xia, who had already become a little teacher, and suddenly laughed.
That perfectly delicate face showed no expression; his small face was stern as he spoke about the key points and considerations of the problem, only missing a pair of antique glasses resting on his nose.
But Xu Renfei also realized that although Bi Xia’s expressionless look made the class seem rigid and uninteresting, in fact, Bi Xia was always able to simplify everyone’s thoughts ingeniously and then use his characteristic cold humor to effortlessly pique their interest.
Unconsciously, he took out his phone and recorded the boy’s every move and word. His almond-shaped eyes narrowed. Damn, he’s really full of charm and incredibly sexy.
Suddenly, Xu Renfei paused and helplessly laughed. Really, since when did he develop this habit of secretly filming...
Meng Luo listened attentively to the young boy’s lecture, then suddenly turned to Meng Chi and seriously said, "You all will win."
Meng Chi was slightly stunned, not understanding.
Meng Luo smiled and looked at Bi Xia on the platform, "Because you have him. Bi Xia is really an amazing child."
Upon hearing Meng Luo’s words, Meng Chi and the surrounding people smiled lightly. They already knew what Meng Luo said. Otherwise, they wouldn’t trust Bi Xia so much, right?
"Let’s end here for today," the bell rang as Bi Xia made the final stroke and turned to pack his preparatory notes, looking at the students below, "Haste makes waste. You can’t just rely on me. Ultimately, it depends on you. What I teach is only the basics, you have to not only watch and practice more but also memorize more. Once you’ve memorized everything, it becomes easier to do anything."
Hearing the students’ responses, his red lips curved slightly, "So, organize your own mistakes and memorize the formulas. If there’s anything you don’t understand, ask me. Next class, Xu Renfei will teach physics."
Walking down the platform back to his seat, Xu Renfei propped his cheek with one hand, his almond-shaped eyes raised teasingly, "Well done, Teacher Xiao Bi."
"You’re flattering me," Bi Xia shot someone a glance and tossed the preparatory notebook on the table, "Worried you can’t teach as well as I did?"
"Indeed," Xu Renfei admitted, "Honestly, I’m a bit nervous now."
Bi Xia chuckled and leaned against the wall, crossing his arms as he looked at Xu Renfei, "The sun must be rising from the west. Didn’t expect King Xu to be nervous."
"Afraid of misleading the students," Xu Renfei stretched lazily and returned to his usual carefree demeanor, "But it’s fine, with Little Jiu Jiu watching below, Brother Qi won’t let Little Jiu Jiu down no matter what~"
Bi Xia snorted lightly, his small face full of disdain, but those star-like eyes sparkled with a hint of a smile.