Introduction to the unit circle | Trigonometry | Khan Academy

Extending SOH CAH TOA so that we can define trig functions for a broader class of angles

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Trigonometry on Khan Academy: Big, fancy word, right? Don't be fooled. Looking at the prefix, tri-, you could probably assume that trigonometry ("trig" as it's sometimes called) has something to do with triangles. You would be right! Trig is the study of the properties of triangles. Why is it important? It's used in measuring precise distances, particularly in industries like satellite systems and sciences like astronomy. It's not only space, however. Trig is present in architecture and music, too. Now you may wonder...how is knowing the measurement and properties of triangles relevant to music?? THAT is a great question. Maybe you'll learn the answer from us in these tutorials!

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[Thaddeusrd]

Khan Academy really needs to learn to utilize the playlist feature.

[arebee]

This is the reason for my chronic depression and prolonged agony.

[sfuikm]

1 hour before my test, wish me luck.

EDIT: I mean a lot of people want to know how the test went, tbh i don't even remember cause it was 2 years ago but i think i passed LOL.

[aye]

good luck to y'all future watchers!

[kuoli]

Much better explained than the Year 11 Math B textbook

[daeinjeon]

His lessons would be more easily understandable if he gave a little more backstory as to why we use the unit circle. This should have been a 2 part series.

[marcosvazquez]

If i ran a school my math department would simply be math tutors while the main curriculum was Khan Academy...

[notgalenangel]

Thank you Khan Academy, you did it again! To anyone reading this, make sure you help those who don't get it yet.

[Malik_Youtube]

I have a rhetorical question that's bothering me for almost 2years, the question is - From where Soh, Cah and Toh came and how did they discover it.

[VictorReyes-rcxp]

Used this to help tutor my classmates, this is truly simpler than it looks and sounds. Thank you! 🙏🏽

[CapeAnneKayaker]

This is the best explanation of the unit circle I have ever seen. It is set up in a way that definitions become clearer and easier to understand. Thank you!

[KMRNUK]

Instead of writing a, b write x, y to make it much better understandable since you are using x, y plane. So sine = y and x = cosine.

[mariamthemaqdisiya]

Man!!!... You deserve the best teacher award, and if there is no such a thing I(regular student from a random country) will be honored to pronounce you as the best! teacher in the world

[evankennedy]

11 hours and 22 minutes till mine and I’m just beginning to learn this stuff

[walimian]

mr.khan is the best teacher i can ever find on youtube. THANKS MR.KHAN

[grey]

maybe i shouldnt have put this off until 1 am on the night before my test words dont make sense in my mind rn

[philipbuckley]

whoa...start at the beginning...what is a unit circle and what is its importance, in trig...

[robertremuszka]

this is amazing! it's helped me so much

[jackmortal]

I feel like I understand this less now

[rlindsay]

Keep them coming Sal! You have been a great help this semester!