Trigonometry

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

Lectures

1. favorites

   Lecture 1 - Basic Trigonometry Part 1

   An introduction to trigonometric functions: sine, cosine, and tangent.

2. favorites

   Lecture 2 - Basic Trigonometry Part 2

   Another example of figuring out the sine, cosine, and tangent of an angle in a right triangle.

3. favorites

   Lecture 3 - Radians and Degrees

   What a radian is. Converting radians to degrees and vice versa.

4. favorites

   Lecture 4 - Using Trig Functions Part 1

   Using Trigonometric functions to solve the sides of a right triangle.

5. favorites

   Lecture 5 - Using Trig Functions Part 2

   A couple of more examples of using Trig functions to solve the sides of a triangle.

6. favorites

   Lecture 6 - The Unit Circle Definition of Trigonometric Functions Part 1

   Using the unit circle to extend the SOH CAH TOA definition of the basic trigonometric functions.

7. favorites

   Lecture 7 - The Unit Circle Definition of Trigonometric Functions Part 2

   Using the unit circle to define the sine, cosine, and tangent functions.

8. favorites

   Lecture 8 - Graph of the Sine Function

   Using the unit circle definition of the sine function to make a graph of it.

9. favorites

   Lecture 9 - Graph of the Trig Function

   Exploring the graphs of trig functions.

10. favorites

    Lecture 10 - Graphing Trig Functions

    Analyzing the amplitude and periods of the sine and cosine functions.

11. favorites

    Lecture 11 - Trig Graphs

    Determining the equations of trig functions by inspecting their graphs.

12. favorites

    Lecture 12 - Determining the Equation of a Trigonometric Function

    Determining the amplitude and period of sine and cosine functions.

13. favorites

    Lecture 13 - Trigonometric Identities Part 1

    Introduction to trigonometric identities.

14. favorites

    Lecture 14 - Proof: sin(a+b) = (cos a)(sin b) + (sin a)(cos b)

    Proof of the trig identity sin(a+b) = (cos a)(sin b) + (sin a)(cos b).

15. favorites

    Lecture 15 - Proof: cos(a+b) = (cos a)(cos b)-(sin a)(sin b)

    Proof of the trig identity: cos(a+b) = (cos a)(cos b)-(sin a)(sin b).

16. favorites

    Lecture 16 - Trigonometric Identities Part 2

    More playing around with trig identities.

17. favorites

    Lecture 17 - Trigonometric Identities Part 3

    Continuation of the playing around with trig identities.

18. favorites

    Lecture 18 - Trigonometry Word Problems Part 1

    The first part of a problem when the captain of a ship goes off track.

19. favorites

    Lecture 19 - Trigonometry Word Problems Part 2

    The second part of the problem of the off-track ship captain.

20. favorites

    Lecture 20 - Law of Cosines

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

21. favorites

    Lecture 21 - Navigation Word Problem

    Trigonometry problem involving two ships colliding.

22. favorites

    Lecture 22 - Proof: Law of Sines

    A simple proof of the Law of Sines.

23. favorites

    Lecture 23 - Ferris Wheel Trig Problem Part 1

    Trigonometry problems dealing with the height of two people on a ferris wheel.

24. favorites

    Lecture 24 - Ferris Wheel Trig Problem Part 2

    Part 2 of the ferris wheel problems. Graph of h(t)=9-8cos(18t).

25. favorites

    Lecture 25 - Fun Trig Problem

    A trig problem involving the quadratic equation.

26. favorites

    Lecture 26 - Polar Coordinates Part 1

    Introduction to polar coordinates.

27. favorites

    Lecture 27 - Polar Coordinates Part 2

    Conversion from Cartesian to Polar Coordinates.

28. favorites

    Lecture 28 - Polar Coordinates Part 3

    Converting between Cartesian and Polar functions.

29. favorites

    Lecture 29 - Inverse Trig Functions: Arcsin

    Introduction to the inverse trig function arcsin.

30. favorites

    Lecture 30 - Inverse Trig Functions: Arctan

    Understanding the arctan or inverse tangent function.

31. favorites

    Lecture 31 - Inverse Trig Functions: Arccos

    Understanding the inverse cosine or arccos function.

32. favorites

    Lecture 32 - Trigonometry Identity Review/Fun

    Revisiting the proofs of some trigonometry identities.