Introduction to Angles (Precalculus - Trigonometry 1)

An introduction to Angles and their usage from standard position on the rectangular coordinate system.

[ProfessorLeonard]

Sorry about the re-posting of this video, I had to fix a mistake :)

[jamescoughlin]

Hello, I am a Calculus instructor at a University in the midwest. I wanted to let you know how much I appreciate your channel as a resource. I have a link to this channel on my course WebSite so that students can review topics that they need to. Your clear and thoughtful explanations are a great service to many. Thank you for the time and effort you put into this channel!

[veryhealthy]

It finally happened! Trigonometry by Prof.Leonard!!!

[Alex-jooi]

I’ve come so far in my 6 week pre calc course. So far averaging 97% and now I’m here for the unit circle, trig functions, etc. Thank you so much Professor Superman.
-From an aspiring Mechanical Engineer.

[marginannotates]

I've been waiting years for you to post Trigonometry lectures! YES! CAN'T TELL YOU HOW HAPPY I AM!

[cubbyhoo]

He's had a haircut! Nice trim prof, your teaching is getting me through Engineering Maths year one, thanks so much!

[engfani]

I've been waiting for Trig for a long time.
I study Engineering and You inspired me to do math videos starting from Pre-Algebra to College Algebra in Arabic.
Thanks.

[issenur]

Professor Leonard And Professor Gilbert Strang and Abdul Bari are responsible for my B.S in Computer Science

[mdphdmfm]

I am impressed with your teaching. Best wishes to you. I am a Professor in Medicine with interest in calculus and Math. You are a teaching star!!

[yasso]

Professor Leonard, I just wanted to tell you that you're a legend. your videos got me through Calc1, 2 and 3 as well as Differential equations over the past 4 years. you've successfully explained what 10k a year engineering school tuition fees couldn't. I really wish you the best, you made me understand what I dreaded I wouldn't during those 4 years. Thank you <3 :) Much love from Turkey

[samuelalasu]

Still changing lives with these thorough lectures!! This man helped me get through calc 3 with ease. Love you Len

[megapril]

Thank you so much Professor!!!! So thankful to have your videos while I am in my undergrad.

[mary]

The best professor of math I could find on the Internet!

[TheSpasmer]

I've waited 2 years for this. Finally. I will now resume my monthly patreon contributions. If you start with linear algebra then I will turn it in to weekly donations

[dineokock]

Thank you for making these videos. I appreciate the effort you put into making these videos.

[GeorgiosMichalopoulos]

I badly needed this before starting your calc 1 course. Many many thanks, you are the best!!

[josiaphus]

So grateful to find a male proper english speaking knowledgeable teacher who cares. Feels like 20 years ago

[viewnys]

This lecture on angles triggered a question for me. I never thought of why 360 degrees in the circle. Why not another number?? i just accepted 360, after taking years of science and engineering courses. Well I looked it up in Wikipedia and found that there is historical ambiguity on its origin. Goes back to the ancient Egyptians, Greeks, etc. There does appear to be some consensus linked to the time of revolution of the sun around the planet, chosen as 24 units, where 360 is convenient mathematical number related to it. I suggest reading it. Quite interesting.

[georgesadler]

Professor Leonard, thank you for a fantastic video/lecture on the Introduction to Angles. In order to understand the angles from a clockwise/counterclockwise direction, using the x-y coordinate system is very useful for understanding angles.

[jasongualito]

Thank you so much finally ! I’ve never got the ability to learn math correctly due to my professor until I found your videos I’m so glad you put Trig! I never learned it !.