English
日本語
한국어
简体中文
Italiano
español
Deutsch
Русский
Proof of Cosine Law
Natz
2025 年 9 月 7 日
I want to walk you through a proof of the cosine law—but with a twist. We’re looking at a case where one of the angles is obtuse. This often feels tricky at first, but with the right tools and a bit of reflection, it becomes beautifully clear.I love this proof because it shows how math builds on itself. Even when things get less intuitive—like with obtuse angles—we can lean on what we already know. If you’ve ever felt unsure about the cosine law in non-right triangles, I hope this helped make it feel more approachable.
專欄文章僅為講師個人觀點，不代表 Cafetalk 立場。
課程
Natz 講師的人氣專欄
-
Coping With Stress Before Exams
Stress has always been part of the lives of not only adults but more so of students. There's ...
Natz
069052019 年 7 月 1 日 -
Hello dear students! I have opened additional slots for my classes here in Cafetalk. What I li...
Natz
067092019 年 7 月 18 日 -
I Don’t Have Gills But I Can Swim
Do you know which is as important as power kicks and arm pulls in swimm...
Natz
066792019 年 7 月 6 日 -
Autumn/Winter 2020 Academic Tutoring Category Award
Dear students and parents,You have been a big part of my achievements and my career as a whole on C...
Natz
046632020 年 12 月 18 日
看此文章的人還閱讀⋯
-
欢迎阅读 Haruka 的中日双语专栏！ Harukaの中日対訳コラムへようこそ！ 我会在这里用中文和日文写一些简短的文章，记录生活的片段和心情的点滴，感谢您的阅读。 如果您正在学习中文，希望我...
Haruka Yao
015702025 年 2 月 15 日 -
Current Hot Topic - the M&S strawberry sando!
When I saw this week's Tutor Column theme 'What is a current hot topic in your country?' there was ...
Liz English
04972025 年 7 月 1 日 -
It's Wimbledon time in the UK! Wimbledon is a world-famous tennis tounament held each summer in Wim...
Hannah N
04352025 年 7 月 5 日 -
(출처 - 유튜브 트와이스 공식 채널)안녕하세요. 이쌤입니다^^여러분은 밸런스 게임을 해보신 적이 있나요?한국에서는 모임, 술자리 등에서 흔하게 하는 게임으로 밸런스 게임 카드...
LEE012
04092025 年 7 月 19 日
回應 (0)