Stop memorizing the unit circle

[khair]

Wow, here I was spending the last hour and a half trying to memorize unit circle, not realizing whatever you Explained is the same thing the textbook was trying to explain. Thank you! It finally makes sense!

[ka]

Currently, I am taking Precalculus that is crazy for 6 weeks a semester, and all I want to say that your lecture is the biggest help for me. You are the best best best teacher. Thank you, Brian

[mattx]

Just got into trig and everyone I know is telling me to just memorize it, and I knew there was a better way; because I've learned that in math you have to understand where the formulas and things come from or you will be lost later on. You are the only explanation I have seen ANYWHERE online that tells how to do this so I really can't thank you enough. It took me a couple of playthroughs but I know this thing completely now and can solve problems my friends have no clue how to start. Thank you, keep them comming!

[jeffreylatham]

It may also help to understand that all of the angles on the unit circle are multiples of 30° or 45°, because we use isosceles right triangle (45°, 45°, 90°) and the (30°, 60°, 90°) right triangle as a reference within the circle to derive our cos&sin values from the lengths of the triangle sides. [1, 1, 2^1/2] and [1, 3^1/2, 2]

radians can seem confusing because of π . However you can use one angle to build all of the others π=180° you can look at 90° as being 1/2 of 180° therefore (1/2)π or π/2. And 45° as 1/2 of 90° and therefore (1/2)(1/2)π or (1/4)π or π/4 this works with all of the angles. 30° is (1/3) of 90° so (1/2)(1/3)π which is (1/6)π or π/6

Once you have your angles down, you can reference your two triangles and use your knowledge of the trig functions to determine your sin/cos values. However there are only 3 sets of values to remember in each quadrant, and ultimately the quadrant determines their signs. Otherwise you have the 1, 0 0, 1 -1, 0 or 0, -1, which lie on the axises

[Amandaleenyc]

Honestly, this whole circle thing never made any sense to me, until now. Brian so far I've used your videos to help me pass 3 separate college level math classes, BRAVO! you're a gem

[bradleymaycroft]

We spent what felt like a week on the unit circle and I had no clue what to do, until you my savor taught it to me in 10 minutes the day before my exam, so thank you!

[mfx]

I don’t get why can’t we just use a calculator. It was created to be used so let us use it. No one will ever have a job and not be allowed to use a calc. gosh.

[CritThinkng]

Had to use my notes (completely drawn unit circle) for my whole calculus class so far, now I don't have to- this made SO much sense. I saw the patterns, this put them into a logical format, thank you!

[billyyang]

for negative radians you can always add 2pi, 4pi, 6pi so on to make the value positive. I think it helps

[AA-gldr]

thank you so much. it’s honestly amazing how unintuitive some companies can make trig when it’s really incredibly intuitive.

Shout out to Pearson for ruining math and thank you to great teachers like this for making it crystal clear!

[nickdaniel]

"I just don't understand, math is so hard. Can you help me with my homework?"
Kid Brian: "No, Dad I have to get on the bus."

[nichroybal]

Much simpler than memorizing the whole circle. However I always get a small sense of accomplishment when I complete it for tests. To each his own. Thank you for all of your amazing content, I'm getting an A in precalc because of your videos!

[ericmontiel]

I used this method and now know how to draw the entire thing without memorization. There's a pattern that you don't even have to memorize. It's simple math. I spent less than an hour on this and can draw a full one perfectly in like 3 minutes or so. Thank you so much Mr. Logan!

[jarcakompova]

Thank you! I am studying to be a teacher of physics, yet I've had problems with memorizing the unit circle since the dawn of my trigonometry knowledge. Now I do not have to fear it anymore. Maybe I'll teach this way to my students one day :)

[hasnashanab]

Me: Wathces the whole video
Also Me: Sneaks in a post it card with the unit circle

[Clueishere]

Going back to University in a few months and haven’t done math in 3 years so this is a great refresher. Thank you!

[clips]

2020 and my teachers still saying I have to memorize...we need more teachers like you :)

[jessconqueso]

You helped me in pre-calc algebra and still coming through for pre-calc trig. I'm so happy you exist, I'm not crying you're crying.

[pratapkarishma]

You can also use the mnemonic ' All Silver Tea Cups' ( first quadrant : all ratios are Positive. 2nd Quadrant: Only Sin ratios are positive. Third quadrant: only tan ratios are positive and 4th Quadrant: all cosign ratios are positive.

[markandrews]

I cannot thank you enough for simplifying this lesson. If people only knew how much time they'd save learning this technique because it is utilised in Physics and Engineering at all levels. My own little spin on this was to cut out a circle and keep folding in half four times....then you have the exactly 16 can fill in the whole thing based on the first quadrant...Thanks once again.