Introduction to Trigonometry: Angles and Radians

Alright, it's time to get into some more challenging math! Trigonometry is a subject that many people find intimidating, but once you understand some new ways to look at angles and some functions that pertain to them, it's really not so bad! First things first, let's make sure we understand what a radian is, and how to measure angles using them!

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[pinklady]

After years of learning mathematics, I didn't really know what a radian was. Thank you for explaining it.

[ontan]

I've been struggling with trig for months because of these topics the video has mentioned. It's explained with a lot of clarity. My teacher goes too fast so I wasn't able to grasp this until now. Thank you so much Professor Dave.

[kevinlehde]

I love your videos - clear, concise, easy to understand. I assign them to my students as a supplement in case they need it. I would nitpick one thing: the very first image shows two rays and calls them "coterminal". But they are not coterminal, because they would be on top of each other. They do start from the same point, but that doesn't make them coterminal. I wouldn't bother mentioning it, but I notice a lot of comments below about whether we can say that two angles are "equal", like pi/2 and 5pi/2. What I would say is that these angles are coterminal - that is, they both end in the same location as you go around the circle. So I would save that word for that use instead.

I really am a fan, I hope this doesn't come off as pedantic. Your takedowns of flat earthers are epic.

[craigasauruswrecks]

Hey! Just noticed at 5:43 The answer for 600 Degrees is inaccurate, taking (600/180) is 3.33repeating. This would give us a fraction of 10(pi)/3 not 4pi/3

[lauramoreno]

His vids are the best and most uncomplicated on YouTube

[KyleGustinSEO]

If only I had found this short video sooner. So much confusion would have been avoided! Thank you!

[trooperzooper]

Basically whoever is getting confused in last question with 600°, Subtract 360 ° from 600° . If you're unsure about an angle like 600 degrees, remember that angles repeat every 360 degrees. Subtracting 360 from 600 gives us 240 degrees, which is the equivalent angle within one full rotation. Converting 240 degrees to radians results in 4/3π. 240/180 is simplified to 4/3.

[georgesadler]

Professor Dave, thank you for a fantastic Introduction to Trigonometry: Angles and Radians.

[udeyukq]

蔡骁驰
0秒钟前
In a numerical sense，the equation 5/4pi is not equal to negative 3/4 pi coz 5/4 is not equal to negative 3/4. I think what you want to express is that in the trigonometric system defined by the unit circle, angle 5/4 pi is logically equivalent to negative 3/4 pi.

[HellooDae]

Are you sure about the last question?

600 degrees is not 4pi/radian, according to my humble calculations. I got 10 pi/3 and I checked online, seems about right.

[ElPurroco]

You are the most brilliant teacher I ever met ...

[nimaemami]

Thank u sooo much!
I am soo excited to start trigonometry!!!

[titanrayven]

Hi Prof Dave! Would it be okay if I link your videos to my learning modules that I created in Canvas? In my canvas, the link of the videos will be posted which will take the students to your channel. Thank you.

[cyklone]

As it turns out, 360 is divisible evenly by every single-digit non-zero integer except 7.

[Sandeepboi]

A great lesson with simple tutorial. I am loving it.

[mr.meeseeks]

Bro my professor made us learn what everything was and what they meant online, which was easy; and when I went to class, he made us come up with formulas and then I thought this class was hard lol tbh he didn't even teach us until after everyone was done solving the problems, and I felt dumb cause most people knew what to do.

[sowmiyafarhath]

Sir, can you explain me? In checking comprehension how 600° = 4π/3

[andresb]

Man you are awesome!!!! You have a gift in ecplain8ng things, thnks a lot!! One of the best videos I've seen about this topic! Regards and my vest wishes, I am a fan now.😀

[ayaansiddiqui]

Trigonometry is not in my syllabus but still I am learning it for competitive exams. Your videos are very useful

[adhiyanthaprabhujeyashanka]

Please clarify Hi professor dave, in checking comprehension, (600degrees to radians) when converting we multiply 600 by π/180 so that must be 10 over 3 times pi(π), please