Law of Cosines

Lecture Description

Introduction to the law of cosines to solve for a side of a triangle when 2 sides and an angle are known.

Course Description

Videos on trigonometry. Watch the "Geometry" playlist first if you have trouble understanding the topics covered here.

Course Index

1. Basic Trigonometry Part 1
2. Basic Trigonometry Part 2
3. Radians and Degrees
4. Using Trig Functions Part 1
5. Using Trig Functions Part 2
6. The Unit Circle Definition of Trigonometric Functions Part 1
7. The Unit Circle Definition of Trigonometric Functions Part 2
8. Graph of the Sine Function
9. Graph of the Trig Function
10. Graphing Trig Functions
11. Trig Graphs
12. Determining the Equation of a Trigonometric Function
13. Trigonometric Identities Part 1
14. Proof: sin(a+b) = (cos a)(sin b) + (sin a)(cos b)
15. Proof: cos(a+b) = (cos a)(cos b)-(sin a)(sin b)
16. Trigonometric Identities Part 2
17. Trigonometric Identities Part 3
18. Trigonometry Word Problems Part 1
19. Trigonometry Word Problems Part 2
20. Law of Cosines
21. Navigation Word Problem
22. Proof: Law of Sines
23. Ferris Wheel Trig Problem Part 1
24. Ferris Wheel Trig Problem Part 2
25. Fun Trig Problem
26. Inverse Trig Functions: Arcsin
27. Inverse Trig Functions: Arctan
28. Inverse Trig Functions: Arccos
29. Trigonometry Identity Review/Fun