正弦/餘弦/正切 | Sine, Cosine and Tangent Ratios
5:21
根據三角比畫三角形 | Construct Triangles based on Trigonometric Ratios
12:43
Trigonometry made easy
21:58
Understand Calculus in 10 Minutes
52:42
09 - Unit Circle - Definition & Meaning - Sin(x), Cos(x), Tan(x), - Sine, Cosine & Tangent
19:45
三角比的延伸定義 | General Definitions of Trigonometric Ratios
3:50
[Math] A highway whose primary directions are north south is being constructed along the coast
9:15
Where do Sin, Cos and Tan Actually Come From - Origins of Trigonometry - Part 1
22:37