# Trigonometry

The foundations of Trigonometry from The Khan Academy.
Instructed by The Khan Academy
• Lectures 32
• Video 5 Hours
• Skill level all level
• Languages English
• Includes Lifetime access
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### Course Description

Videos on trigonometry. Watch the &#039;Geometry&#039; playlist first if you have trouble understanding the topics covered here.

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• Over 32 lectures and 5 hours of content!

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### Curriculum

 Lecture 1 08:44 An introduction to trigonometric functions: sine, cosine, and tangent. Lecture 2 05:54 Another example of figuring out the sine, cosine, and tangent of an angle in a right triangle Lecture 3 09:55 What a radian is. Converting radians to degrees and vice versa. Lecture 4 10:02 Using Trigonometric functions to solve the sides of a right triangle Lecture 5 08:37 A couple of more examples of using Trig functions to solve the sides of a triangle. Lecture 6 09:07 Using the unit circle to extend the SOH CAH TOA definition of the basic trigonometric functions. Lecture 7 10:11 Using the unit circle to define the sine, cosine, and tangent functions Lecture 8 07:44 Using the unit circle definition of the sine function to make a graph of it. Lecture 9 10:16 Exploring the graphs of trig functions Lecture 10 09:53 Analyzing the amplitude and periods of the sine and cosine functions. Lecture 11 05:12 Determining the equations of trig functions by inspecting their graphs. Lecture 12 09:51 Determining the amplitude and period of sine and cosine functions. Lecture 13 09:10 Introduction to trigonometric identities Lecture 14 09:48 Proof of the trig identity sin(a+b) = (cos a)(sin b) + (sin a)(cos b) Lecture 15 09:22 Proof of the trig identity: cos(a+b) = (cos a)(cos b)-(sin a)(sin b) Lecture 16 09:56 More playing around with trig identities Lecture 17 08:35 Continuation of the playing around with trig identities Lecture 18 09:56 The first part of a problem when the captain of a ship goes off track. Lecture 19 02:51 The second part of the problem of the off-track ship captain Lecture 20 09:26 Introduction to the law of cosines to solve for a side of a triangle when 2 sides and an angle are known. Lecture 21 08:00 Trigonometry problem involving two ships colliding. Lecture 22 06:32 A simple proof of the Law of Sines Lecture 23 07:20 Trigonometry problems dealing with the height of two people on a ferris wheen Lecture 24 09:07 Part 2 of the ferris wheel problems. Graph of h(t)=9-8cos(18t) Lecture 25 10:01 A trig problem involving the quadratic equation. Lecture 26 10:20 Introduction to polar coordinates Lecture 27 09:31 Conversion from Cartesian to Polar Coordinates Lecture 28 07:37 Converting between Cartesian and Polar functions Lecture 29 10:36 Introduction to the inverse trig function arcsin Lecture 30 10:06 Understanding the arctan or inverse tangent function. Lecture 31 13:38 Understanding the inverse cosine or arccos function Lecture 32 11:07 Revisiting the proofs of some trigonometry identities.

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### Reviews

Average Rating
4.3
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• Chris Yarrison

#### Good review

I was looking for a refresher, and this is a good one. However, I would not recommend it to someone learning trig for the first time.

• Andreu Ortin

#### Trigonometria

Vídeo tutorials de trigonometria.

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