TR-33Z: All Trig Functions on the Unit Circle (Trigonometry series by Dennis F. Davis)

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  • Опубліковано 30 січ 2025

КОМЕНТАРІ • 69

  • @maninimahapatra649
    @maninimahapatra649 2 роки тому +17

    I've always heard "sine" "cosine" nd other stuff are just "ratios that you need to memorize". But this diagram just explains it all. Like how they just put the prefix co- for every line in the opp direction to the main line and how the big formulas were derived. All of it depicted in seconds. It amazing bro, love you

    • @crysania1980
      @crysania1980 10 місяців тому

      I love him too :) Watch me get my A in Precalculus in a month :)

  • @capeandcode
    @capeandcode 2 місяці тому

    Sir, this is the second video of your that I have watched and I proclaim you among the top 3 people I have seen who teach maths the way it should be taught. Massive Respect!

  • @iceiceisaac
    @iceiceisaac 3 роки тому +28

    Man, this is too cool. I knew there had to bee more to it. Wonder why schools decide to teach the way they do.

    • @maninimahapatra649
      @maninimahapatra649 2 роки тому +3

      ikr, their way is both incompetent and inefficient. Why the hell they even adopt it

    • @mathsfornineyearolds
      @mathsfornineyearolds 2 роки тому +2

      Algebra is a good way of confusing people when you are trying to teach trig. The maths teachers probably avoid it when explaining it to their own children. The teachers are given a curriculum and have to teach it as instructed. The internet has taken this out of their hands. I was told the intention is to keep all the students at the same level.

    • @Cono10YT
      @Cono10YT Рік тому +1

      My teacher showed us this video in class. I live in Barcelona, Spain.

    • @ull893
      @ull893 Рік тому +2

      ​@@Cono10YT your teacher is great. Lucky you ✌️

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому +5

      @@Cono10YT How interesting! So I'm now an international UA-cam personality!

  • @Janet2801
    @Janet2801 3 місяці тому

    I have been looking for this kind of video forever, thank you so much for making this video and making a significant impact to all learners!!

  • @astainment8543
    @astainment8543 Рік тому +2

    I was always confused about these functions, but after watching your video, everything became clear. Thank you sir. And thank God that I found your channel❤....

  • @ull893
    @ull893 Рік тому +2

    Yours is the ONLY video that explains all of these so clearly. Also I was VERY confused about why tan line was shown in two different ways. You made it a point to explain that also🙏.... Not enough words to say thank you. ❤️❤️❤️❤️❤️After so many years of learning trigonometry, finally it makes sense. Thank you again.

  • @erlexar
    @erlexar 3 роки тому +2

    This is a great video. It’s helping me visualize in how to coordinate this concrete slab I have to lay out at work.

  • @suyapajimenez516
    @suyapajimenez516 2 роки тому +2

    Professor Davis your videos are son neat and beautiful and your explanation spotless. I hope you keep uploading more and more enlightening classes. Congratulations and thanks

  • @monoman4083
    @monoman4083 2 роки тому +2

    you deserve loadsa views. keep going please..

  • @ΒΑΓΓΕΛΗΣΜΠΙΣΤΑΣ-μ3θ
    @ΒΑΓΓΕΛΗΣΜΠΙΣΤΑΣ-μ3θ 4 місяці тому

    Your analysis was illuminating!

  • @rameshsinghtomar4018
    @rameshsinghtomar4018 3 роки тому +3

    You are doing well.just keep it up.

  • @josephlai9759
    @josephlai9759 2 роки тому +1

    Thank you so much. Elegance par excellence.

  • @bjornfeuerbacher5514
    @bjornfeuerbacher5514 Рік тому +1

    Most is very nice. :-) But in the animation, abozt 6:45, it's not clear how one can see that the value of tan is now negative.

  • @ull893
    @ull893 Рік тому

    The only trigonometry video that gave me goosebumps 😂😂😂. ❤🌹✌️

  • @vanastrearein2744
    @vanastrearein2744 3 роки тому

    OMG This video made my trig paper so much easier. TYSM

  • @ockham1963
    @ockham1963 2 роки тому

    Brilliant Trig teacher

  • @manishbhatnagar82
    @manishbhatnagar82 2 роки тому +1

    RESPECTED SIR, YOU ARE GOD OF TRIGONOMETRY 🙏 !!!!....

  • @cruzergo
    @cruzergo 2 роки тому +2

    The half roof slope length (cotangent) of my house is equal to the half length ceiling (cosine) of my house divided by the height of the house wall (sine). To think of it in practical terms. Looks like a half house to me.

  • @file4318
    @file4318 Рік тому +1

    Hello, I absolutely love your videos. I am curious, what software do you use to animate the math?

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому +1

      Hi File, thanks for your viewership!
      I mostly use painstakingly-crafted PowerPoint with the morph transition to provide the animations.

  • @mathsfornineyearolds
    @mathsfornineyearolds 2 роки тому +1

    get an A 2 size paper and draw the lot on a circle. The object is to show the calculations for finding the coordinates and, or angles from any two variables and be able to draw and show them on a circle. Then you have mastered the maths. Then you have to apply them to nature. For example, the resonance distance of a sound wave that produces an echo for the science of acoustics, or the art of music.

  • @shi_mo_neta
    @shi_mo_neta 2 роки тому

    6:28 "..the relationship between sine and secant, how they just touch at the quadrantal angles." I am unable to see this. Were you referring to the reciprocal relationship between sine and *cosecant, because their graphs touch when both of them are 1 at θ = nπ + π/2.

    • @DennisDavisEdu
      @DennisDavisEdu  2 роки тому +1

      You are right! I misspoke in the video. The "just touching" relationships occurs between [sine and cosecant] and [cosine and secant]. Thank you for paying such close attention!

    • @maninimahapatra649
      @maninimahapatra649 2 роки тому

      This Asian dude givin me the vibes now lmaoo 😂😂😂
      A genius pro gamer vibes

  • @bigk2367
    @bigk2367 Рік тому

    I had this silly question at 3:17 and 4:09
    that How can we prove both are similar triangle?

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому

      If we can show that two triangles have two common angles then they must be similar. All of the triangles in this video are similar to each other: They all have a right-angle of course and the other two angles are θ and the complement of θ.
      At 3:17, the topmost (smallest) angle in the "cotangent" triangle is the complement of θ. In the lower left corner of the coordinate system (at the origin) you can see that this angle plus θ is a right angle so it's complementary to θ.
      For the other triangle (that has sin and cos) you can see its angle at the yellow dot. It's in a right triangle across from angle θ, so it must also be complementary to θ.
      There aren't any other angles in the whole diagram. Every angle is either a right angle, θ or θ's complement.

    • @bigk2367
      @bigk2367 Рік тому +1

      @@DennisDavisEdu Oh yup!! I am so grateful for your reply! You are a great teacher! Thank you🙏😀

  • @EmperorFowl
    @EmperorFowl Рік тому

    Talk about seeing things in a new light. The trig functions are so much more real when you see them displayed like this. Also Makes it WAY easier to remember the domain and range of these functions

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому

      I agree Tim, this construction makes a lot of trig seem clearer. Thank you so much for all of your nice comments, I read them all!

  • @maya7814
    @maya7814 Рік тому

    Hi Dennis.Thanks for the wonderful videos. i was just wondering how you determine dsecant and cosecant as purple and pink lines on the graph?

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому

      I'm not sure I understand the question, it's in this video at 3:43, right?

    • @maya7814
      @maya7814 Рік тому

      @@DennisDavisEdu Yes exactly.I didn't understand as to how the purple line is made as secant and pink line as cosecant on the graph.

    • @DennisDavisEdu
      @DennisDavisEdu  Рік тому

      It's shown with similar triangles:
      Purple over Yellow equals Yellow over Blue. Purple over Yellow is Purple since Yellow is 1. Yellow over Blue is 1/cos. That's the definition of Secant so Purple equals Secant.
      Pink over Yellow equals Yellow over Red. Pink over Yellow is Pink since Yellow is 1. Yellow over Red is 1/sin. That's the definition of Cosecant, so Pink equals Cosecant.

  • @swacademy
    @swacademy 2 роки тому

    Awesome!!

  • @BoZhaoengineering
    @BoZhaoengineering 2 роки тому

    Sir, just a quick question. You show the identities in the actuate angle situation , saying, 0

    • @DennisDavisEdu
      @DennisDavisEdu  2 роки тому +1

      All of the identities covered in TR-33 through TR-41 are true for all angles, acute and obtuse. The exception would be they are not true for angles where one of the terms is undefined. For example, tanθ = sinθ/cosθ is always true EXCEPT where cosθ = 0.
      I use acute angles when proving the identities geometrically because they are more convenient to see and draw, but the identities can be generalized to all angles.
      Thanks for watching and for your kind comments!

    • @maninimahapatra649
      @maninimahapatra649 2 роки тому

      How can you have a theta greater than 90 deg in a right angle triangle? It'd break the 'Angle sum property' of a triangle you know.

    • @DennisDavisEdu
      @DennisDavisEdu  2 роки тому

      @@maninimahapatra649 See video TR-14: ua-cam.com/video/oJgBJfstOOU/v-deo.html

  • @greedskith3020
    @greedskith3020 2 роки тому +1

    Sooooooooo useful!!!

  • @amirk6290
    @amirk6290 2 роки тому

    I love this video ❤️

  • @thezaheerali
    @thezaheerali 2 роки тому

    Thanks many 👍💞💞💞💞

  • @raunox5938
    @raunox5938 Рік тому

    this is now where near all the trig functions
    could you please do one for Sgn(x), Si(x), Sin(z), Cos(z), Tan(z), Cosh(x), Tanh(x), Sinh(x), Sech(x), Csch(x), Coth(x), ArcSin(x), ArcCos(x), ArcTan(x), ArcCsc(x), ArcCot(x), ArcSec(x), ArcSinh(x), ArcCosh(x), ArcTanh(x), ArcCsch(x), ArcCoth(x)?

  • @mukhtaarjaamac8763
    @mukhtaarjaamac8763 3 роки тому +2

    Please and please compond angle double angles and half angles proof like this .best way

    • @DennisDavisEdu
      @DennisDavisEdu  3 роки тому +1

      Yes I will cover those topics in future videos.
      I was going to finish the entire series before I published any, but I've completed to about TR-34 or TR-35 and decided to publish what I had ready. So videos after these will not come out as frequently because I'm all caught up with what I've been working on the past 2 years.

    • @maninimahapatra649
      @maninimahapatra649 2 роки тому

      @@DennisDavisEdu what have you been working on for the part 2 yrs...? very intriguing. What is it?

  • @Gabriel-jp5dl
    @Gabriel-jp5dl Рік тому

    i knew there had to be more to trig :)

  • @xeyaleqarayeva5218
    @xeyaleqarayeva5218 3 роки тому +1

    Супер 😊

    • @DennisDavisEdu
      @DennisDavisEdu  3 роки тому +1

      Спасибо за ваш приятный комментарий!

  • @SoloRenegade
    @SoloRenegade 2 роки тому

    why this isn't taught in every trig class......

  • @jbergamp
    @jbergamp 2 роки тому +1

    I saw the sign and it open my mind i saw the light (ace of base)

    • @DennisDavisEdu
      @DennisDavisEdu  2 роки тому

      Just punch the "Demo" key on any old Casio keyboard and you've got an Ace of Bass song! I'm glad my video opened your mind.

  • @Luizabf
    @Luizabf Рік тому

    Maravilha

  • @mukhtaarjaamac8763
    @mukhtaarjaamac8763 3 роки тому

    And graph one by one animation

  • @NexushasTaken
    @NexushasTaken Рік тому

    goshh i hate myself, in all of the videos about trig functions, i can't still understand!!
    the only functions that i understand is sine and cosine; and the rest is confusing!!

    • @simpleman283
      @simpleman283 Рік тому

      Try this video. It helped me a lot. It's only 8 minutes long.
      ua-cam.com/video/Dsf6ADwJ66E/v-deo.html

  • @aLittlePal
    @aLittlePal Рік тому +2

    thank you Denny. sir I love you and I love math as well.

  • @aLittlePal
    @aLittlePal Рік тому +1

    by youtube algorithm I accidently watched the animation first, now I'm watching the proving/proof part. it all makes sense.

  • @smileitsfreeanditwillmakes4121

    This guy talks to fast to be taken seriously also he says "dont" alot something real educators avoid doing.