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If solving trigonometric equations is your idea of fun, then this video is correctly titled. Here Sal uses trigonometric identities, the quadratic formula, and inverse trigonometric functions to solve a trigonometric equation sent in by...

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### We found 166 resources with the keyterm Trigonometry

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Lesson Planet: Curated OER

#### Trig Identities Part 3 (Part 5 if you watch the proofs)

Sal takes the mystery out of the trigonometric identities by showing how easily they can be derived. He continues with a problem he started in the video ï¿½Trig identities part three (part five if you watch the proofs) and proves the trig...

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#### Trigonometry Work Problems (Part 2)

In this part two video, Sal finishes the trigonometric word problem of the wayward ship captain. He wisely continues the algebra work on the problem before finally turning to his calculator for the very last calculation.

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#### The unit circle definition of trigonometric function

In this video, Sal shows how the sine and cosine of an angle are defined on the unit circle. He inscribes a 30-60-90 triangle in the unit circle and explains how one can use SOH-CAH-TOA to find the coordinates on the circle.

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#### Trigonometry Word Problems (Part 1)

Sal starts to solve a trigonometric word problem of a wayward ship captain who veers off course and once aware of his predicament, needs to know how far he is from his destination. Instead of using the Law of Cosines in his solution, Sal...

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#### Trigonometric System Example

Sal solves a challenging problem that consists of a system of three trigonometric equations and three unknowns.

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#### Trig Identities Part 2 (Part 4 if you watch the proofs)

In this video, Sal reviews the basic trigonometric definitions and identities including the sum of angles formulas and then derives the double angle formulas.

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#### Proof: sin(a+b)=(cos a)(sin b)+(sin a)(cos b)

Sal proves the sum of angles formula for sine, sin (a+ b) = cos (a) sin (b) + sin (a) cos (b), through a clear but rather non-intuitive proof. The proof is interesting as it not only uses the SOH-CAH-TOA model but requires one to recall...

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#### Proof: cos(a+b)=(cos a)(cos b)-(sin a)(sin b)

Using a similar method that he used to prove the sum of angles formula for sine, Sal shows the proof of the cosine sum of angles formula, cos (a+ b) = cos (a) cos (b) - sin (a) sin (b). This proof also uses the SOH-CAH-TOA model and some...

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#### Polar Coordinates 1

In this introductory video, Sal defines polar coordinates and using basic trigonometry identities and the Pythagorean Theorem defines the relationships between Cartesian coordinates and polar coordinates.

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#### Fun Trig Problem

If solving trigonometric equations is your idea of fun, then this video is correctly titled. Here Sal uses trigonometric identities, the quadratic formula, and inverse trigonometric functions to solve a trigonometric equation sent in by...

Lesson Planet: Curated OER

#### IIT JEE Trigonometry Constraints

Sal solves a challenging trigonometric problem for finding the number of values of _ that satisfy a number of constraints over a given interval. He shows a clear step-by-step solution and uses some trigonometric identities that he derives.

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#### IIT JEE Trigonometry Problem 1

Sal solves an interesting question in this video from a college entrance exam in India that requires one to use knowledge of arithmetic progressions, trigonometric identities, and algebra. He works through solving the problem in a...

Lesson Planet: Curated OER

#### Inverse Trig Functions: Arccos

In the third video on inverse trigonometric functions, Sal follows a format similar to the last two. He finds the value for the arcos (-1/2) and shows the restricted domain of the arccos function. He also finds the value for cos(arccos...

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#### Inverse Trig Functions: Arctan

Continuing with inverse trigonometric functions, Sal finds the value for tan^-1-1. He also shows the restricted domain of the arctan function.

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#### Inverse Trig Functions: Arcsin

Sal defines the concept of inverse trigonometric functions and completes two examples of arcsin. Specifically, he finds the value of the arcsin (sqroot2/2) and arcsin (sqroot3/2). He also talks about the restricted domain of arcsin...

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#### Fun Trig Problem

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#### Ferris Wheel Trig Problem (part 2)

Sal continues the Ferris wheel problem in a previous video by graphing the function between zero and 30 seconds.

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#### Ferris Wheel Trig Problem

The next time you are at an amusement park you may want to consider all the interesting math problems you could do! Using trigonometric ratios, some logic and algebra, Sal solves a problem in this video of finding a person's height off...

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#### Proof: Law of Sines

In this video, Sal proves the Law of Sines by using the SOH-CAH-TOA model and setting up equivalent ratios.

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#### Law of Cosines

Sal derives the Law of Cosines using a method similar to the wayward ship captain word problem he solves in another video. This video provides a good review of using the SOH-CAH-TOA model, the Pythagorean Theorem, some of the basic trig...

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#### Trigonometry work problems (part 2)

In this part 2 video, Sal finishes the trigonometric word problem of the wayward ship captain. He wisely continues the algebra work on the problem before finally turning to his calculator for the very last calculation.

Lesson Planet: Curated OER

#### Proof: cos(a+b)=(cos a)(cos b)-(sin a)(sin b)

Using a similar method that he used to prove the sum of angles formula for sine, Sal shows the proof the cosine sum of angles formula, cos (a+ b) = cos (a) cos (b) - sin (a) sin (b). This proof also uses the SOH-CAH-TOA model and some...

Lesson Planet: Curated OER

#### Intro to the Trigonometric Ratios

This video introduces the basics of trigonometry. It starts by defining a right triangle and showing two different examples of finding the ratios of sine, cosine, and tangent using the SOH-CAH-TOA mnemonic. This resource could be used as...

Lesson Planet: Curated OER

#### Hubble's Law

Sal defines and explains the premise of Hubble's Law and then uses trigonometry to show the relationship between velocity and distance. He explains that as the universe expands, objects get farther away from each other; as objects move...