05 - Sine and Cosine - Definition & Meaning - Part 1 - What is Sin(x) & Cos(x) ?

Поділитися
Вставка
  • Опубліковано 22 чер 2020
  • View more at www.MathAndScience.com. In this lesson, we will learn fundamentally what the sine function and cosine function represent. We will learn that the sine function, also written as sin or sin(x), reduces the hypotenuse of a right triangle to the projection onto the y-axis. Similarly, the cosine function, also written as cos or cos(x), reduces the hypotenuse of a right triangle to the projection onto the x-axis. Thinking of sine and cosine as projection functions like this helps us to visualize exactly what the sin(x) and cos(x) functions do. This has applications in math, engineering, physics, and all branches of science.

КОМЕНТАРІ • 2,8 тис.

  • @halbertthomas7818
    @halbertthomas7818 3 роки тому +1462

    I'm a happy 75 year old. Thought I was math-hopeless. I got this lecture totally. Wish I seen this 50 years ago.

    • @eng560
      @eng560 3 роки тому +25

      It's very nice

    • @TanujRoy
      @TanujRoy 3 роки тому +20

      Thanks so much, I always wondered what sin cos tan were

    • @rafimohmmed5939
      @rafimohmmed5939 3 роки тому +10

      Me toooooo

    • @MathAndScience
      @MathAndScience  3 роки тому +88

      Awesome!

    • @kierandevine9202
      @kierandevine9202 3 роки тому +38

      You are confusing math with teachers that only know what the book says the answer is, they are hopeless.

  • @etcetera3282
    @etcetera3282 3 роки тому +260

    If I had you as my math teacher in high school, my life would have gone to a different direction. Clear & Simple.

    • @stevekru6518
      @stevekru6518 3 роки тому +7

      In several other first world countries you would have had a math teacher like this, but it would’ve been in late elementary school, not high school. This hypothetical teacher would not have had union pressuring the state to hire only education majors, excluding math and science majors.

    • @simplypqz
      @simplypqz 3 роки тому +6

      omg ikr??? maybe we would be nuclear scientists or something.

    • @joescola7498
      @joescola7498 3 роки тому +2

      I had a teacher like him in high school. Mr Nelson, Medford High, Medford MA.

    • @speedoflight3395
      @speedoflight3395 2 роки тому +2

      You had a teacher like him in high school. You just weren't ready to learn when you were in high school.

    • @etcetera3282
      @etcetera3282 2 роки тому +3

      @@speedoflight3395 Are you a Nigerian who practices Vudoo?

  • @MrLabrat1974
    @MrLabrat1974 2 роки тому +70

    I'm 65 and taking college trig right now. I haven't done any trig for almost 50 years and these videos are like a breath of fresh air. I learn something better if I know the why and not just the how.

    • @yuvraj9797
      @yuvraj9797 Рік тому +4

      Keep on Old timer.

    • @joycebruhn1346
      @joycebruhn1346 10 місяців тому +3

      Good for you. It’s great to be lifelong learner

  • @skillybiskuit12
    @skillybiskuit12 2 роки тому +48

    I almost didn’t graduate high school because of math. I slipped behind once and never caught up again. Fast forward, I’m 22 and I’ve decided to spontaneously pursue physics. I watch your videos religiously. I didn’t realize how highly intelligent I could be with the correct teacher. Your work is very much appreciated thank you for your quality and dedication

  • @charlietrece7958
    @charlietrece7958 3 роки тому +87

    If a man keeps me interested over 40 minutes in something that I have no idea what’s he’s talking about it’s because the man knows what’s he’s talking about and suddenly trigonometry feels right. My respects to this teacher.

    • @leagomaity6151
      @leagomaity6151 2 роки тому

      Fantastic stuff I really enjoy math like I have never before ,I used to be bad in trigonometry but now it's a different story

    • @marianbinny3529
      @marianbinny3529 2 роки тому

      Attention deficit is causing the problem
      So rectify ur attitude
      Thanks 😀😂😂🐒👍⛵💯

  • @platoeuclid7053
    @platoeuclid7053 3 роки тому +153

    As a fellow math teacher, I can say that this is an excellent video as he does a great job of explaining the ‘WHY’ of the data. Well done.

    • @hychap
      @hychap 2 роки тому +1

      How can you put in 5N and get out 4N and 3N?!
      If I had to build a dye requiring a 4N force right and a force of 3N up.. could I achieve that?
      If that is true, then wouldnt a magnetic force also work along the same principle and be proof for over unity?

    • @cottoncandycloudsrobloxedits
      @cottoncandycloudsrobloxedits Рік тому

      @@hychap idk if I'm understanding what your confused about right but, you put in 5 as the hypotenuse of a right triangle and since it's a right triangle the other sides have to be 3 and 4

    • @ronalddump4061
      @ronalddump4061 Рік тому +4

      @@cottoncandycloudsrobloxedits No they dont, the lengths of the legs can be any of an infinite number of lengths if the hypot is 5.
      He just CHOSE a 3/4/5 triangle as an example

    • @cottoncandycloudsrobloxedits
      @cottoncandycloudsrobloxedits Рік тому

      @@ronalddump4061 oh sorry I'm just learning this so i must've misunderstood

    • @ronalddump4061
      @ronalddump4061 Рік тому +5

      @@cottoncandycloudsrobloxedits Obviously if hypot is 5 one of the legs can be anything between 0 and 5, right? That is an infinite number of possibilities. He just chose the 3/4/5 for convenience. Round numbers

  • @financialservicesprofessio7377
    @financialservicesprofessio7377 Рік тому +34

    Dear Teacher, I am writing to inform you that for the first time in my life (I'm 55 years old), I have finally understood the Trig functions concept. I have read a million times, over the years that the angle sin0 is Opp/Hyp, but I have never understood what the heck everyone was talking about until I watched this videos. Everything fits into place for me now. Why am I even watching this video at the age of 55? Well, my daughter is struggling with this concept as well. I wanted to revisit the topic and see if I could help her. I am glad I found you. Over the years that I have watched your videos, I think you are the most effective teacher I have ever seen. The concept of "chopping factor" is a miracle. Concept this simple, I don't know why the teachers can't really explain it clearly to their students. Could it be that they themselves are just repeating what they memorized, without any understanding?

  • @claudeelliott3993
    @claudeelliott3993 2 роки тому +32

    I'm a mostly happy 88 year old who had major problems with math in high school. You, sir , broke through a lot of ancient haze tonight for which I'm grateful since I can "assume" that maybe I'm not as dumb as I thought ! Thank you for your patience and clarity in explaining sin and cosine.

  • @tomd9275
    @tomd9275 3 роки тому +110

    I’m pretty sure most observers feel that they would have had not only a better understanding of the subject, but ,also would have enjoyed the lesson and presentation.
    This gentleman was born to teach.
    Humble and erudite..Bravo!

  • @geekmafia9654
    @geekmafia9654 3 роки тому +247

    This world needs teachers like you. You are just diamond. Thank you very much for your knowledge for your passion for your time.

    • @stevekru6518
      @stevekru6518 3 роки тому +10

      No, this country, which is behind most first world countries in STEM education, needs THIS teacher to replace the education majors who cannot teach a subject they themselves do not understand. Instead of the unrealistic goal of having thousands of teachers like this one, broadcast this lesson into thousands of classrooms replacing ineffective teachers. Much better results at much lower cost.

    • @jimja395
      @jimja395 3 роки тому +3

      👌👌👍👍👏👏

    • @ateri9715
      @ateri9715 3 роки тому +1

      I know you are saying this with a good intention but diamonds arent expensive or rare , they are actually more common than you think . Their market value is high but their actual value is so much cheaper than that

    • @wodeyaeric5351
      @wodeyaeric5351 2 роки тому +3

      He is the best at his topic. I wish he could also break down calculus and simultaneous equations into their intuitive versions. None of us is bad at math I am realizing. It is just how we r taught that messes us and bruises our confidence in the process.

    • @wodeyaeric5351
      @wodeyaeric5351 2 роки тому +1

      @@stevekru6518 not most classes possess smartphones or even data.

  • @capri2673
    @capri2673 2 роки тому +14

    Just for interest, I started a STEM degree at 49 and now we're onto maths, which was my least favourite subject at school. This has been very helpful. Seeing cos, sin, etc. being described in such a practical has made it so much easier to learn. Thanks. I wish we'd had UA-cam in the 80s!

  • @Kerrsartisticgifts
    @Kerrsartisticgifts 5 місяців тому +1

    When I was a kid in Glasgow, I was sent to Secondary school a year and some months early. I was put into "Prep A" and I was taking math, chemistry and physics as well as the usual classes, English, Art and Music. I was put into a course with a few other kids, called "New Math" . The only problem was major. I had never heard of anyone being sent "ahead" so I took it as rejection and thought my teachers did it to be rid of me, because I was the boy with the problem, I asked too many questions. I was also from a poor working class family and had to leave school to work at the earliest opportunity. I knew that but my teachers didn't.
    I had to leave at 15 yrs and I went to work 6 days a week and gave my wages to my mother. I was the sole support for my mother, myself and two brothers at 15 years old.
    I am 69 now and still read educational and scientific materials all day, every day. I wish I could sit in on university lectures and just learn

  • @bouchrabensellam6657
    @bouchrabensellam6657 3 роки тому +68

    I m 45 years old I love Math but really I wish we had UA-cam on our days 💔 I keep watching your videos till 4:00 am they are much enjoyable than Netflix 😇

    • @Simon-xi8tb
      @Simon-xi8tb 3 роки тому +4

      dude, have you seen Breaking Bad ?

    • @roysmith3198
      @roysmith3198 3 роки тому +3

      That sounds like me, why watch distractions when you can learn/do. 😎

    • @Simon-xi8tb
      @Simon-xi8tb 3 роки тому +2

      @@roysmith3198 said no one with ADHD ever

    • @pcchin3920
      @pcchin3920 3 роки тому +1

      Poor me. Now 83 ,but in my teenage schooldays had to learn maths not undertandin

    • @omegalamda3145
      @omegalamda3145 3 роки тому

      @@pcchin3920 not to worry, the lucky part is you came upon this video at the right time. Nice calculus!

  • @hrshl4644
    @hrshl4644 3 роки тому +208

    Just realised I wasn’t dumb my foundation was weak af

  • @seankeikbusch9404
    @seankeikbusch9404 2 роки тому +1

    Never imagined I'd be an exbricklayer watching a math video for my own enjoyment on sunny Saturday afternoon but here I am.

  • @narasingaraj6057
    @narasingaraj6057 16 годин тому

    I am 75 years, and I had you as my Maths teacher in final years my of school days, my carrier might have taken in differant Direction.

  • @gordonclark7632
    @gordonclark7632 3 роки тому +86

    I was intrigued and now wish I had this understanding 45 years ago when I was in school.

  • @cholan2100
    @cholan2100 3 роки тому +64

    With access to this high quality of educational content online, poor third world like where I live might finally get a chance to compete. Thanks mate.

    • @tonyfremont
      @tonyfremont 3 роки тому +11

      The internet has really leveled the playing field for educational opportunities around the world.

    • @stevekru6518
      @stevekru6518 3 роки тому +1

      The US ranks poorly among other first world countries in primary and secondary STEM education. The US needs this educational content to replace education majors who cannot teach what they do not understand

    • @ailleananaithnid2566
      @ailleananaithnid2566 3 роки тому

      @@stevekru6518 You said it!

    • @mathfullyexplained
      @mathfullyexplained 3 роки тому +1

      Try my channel mathfullyexplained. Full unit on right triangle trigonometry plus more units

  • @NottiBop628
    @NottiBop628 Рік тому +17

    I'm in 8th grade preparing for next year and you are somehow able to convey these concepts to me perfectly. Thank you.

  • @wondergames92
    @wondergames92 2 роки тому +13

    If everyone had a teacher like you we'd be living in a much better world

  • @deirdreberger1363
    @deirdreberger1363 4 роки тому +307

    This is amazing. You are a very talented teacher. Your dedication and passion shows in the high quality of your work.

  • @coldstreamreiver9870
    @coldstreamreiver9870 3 роки тому +7

    We only learned how to use Sin and Cos. Finally, at the age of 61, I have finally understood them. A massive thank you.

    • @mathfullyexplained
      @mathfullyexplained 3 роки тому

      Try my channel mathfullyexplained. Full unit on right triangle trigonometry plus more units

  • @supergeek0177
    @supergeek0177 2 роки тому

    I wish I had this guy back in high school 20 yrs ago - I could have actually studied engineering instead of being stuck in shit jobs lol.
    But here I am in my mid 30s at Uni having to learn parts of stuff I never even learnt in school properly. And I find myself scrolling thru UA-cam for decent videos since all the lecturers assume you know this stuff lol.
    Thankyou, Sir! Seriously Thank-you!

  • @kayseychapmancisneros7490
    @kayseychapmancisneros7490 2 роки тому

    I feel like I should be paying this guy $326 per credit hour. There have been some definite holes in the information I'm getting from my college professor and he filled in the gaps. THANK YOU!

  • @Tate.TopG.
    @Tate.TopG. 3 роки тому +4

    I graduated A engineer but I can say that I never say math made so easily to understand. I wished most math professor were like you. More people would definitely love math.

  • @vijay7415
    @vijay7415 3 роки тому +13

    It is unusual for someone who is 69 yrs old sitting in the late evening at his home in India, watching this. Despite the drawback of catching up with the speed and accent (i relied on CC), I really felt that I would roll back to 55 years and sit in my class again and listen aptly the mathematical jargon. I really remember my high school Maths teacher talking Sin Teta and Con Teta and forced to learn those things. I would love to be a Maths teacher...but...you know, I keep listening to you as to when youtube obliges me. Thank you, Sir.

    • @MathAndScience
      @MathAndScience  3 роки тому +3

      You are very welcome!

    • @B._Smith
      @B._Smith 3 роки тому +1

      Remember you can also slow down the playback speed to 0 75 if it helps.

    • @ferdinichols4322
      @ferdinichols4322 3 роки тому +1

      Very reliable and sincere. Thanks.

  • @javediqbal8593
    @javediqbal8593 14 днів тому

    Being a PhD in mathematical statistics, this is the first time I understood what the sin and so are. Salute to this huy. related subject

  • @cullenpenny8574
    @cullenpenny8574 3 місяці тому

    Thank you Prof, I am 71 years old and, for the first time, I understand what Sin and Cos mean, rather than learning it by rote. Wish I had known this years ago, but hey, never too late,

  • @AngusandAndrewfunguys
    @AngusandAndrewfunguys 3 роки тому +24

    At my school in Drumchapel, Scotland in the sixties I was completely confussed by trigonometry. After this lesson I now understand the meaning of Sine & Cos and now I just want to learn more from you to prove to myself I was not really the dummy I thought I was. Keep doing what your doing, it makes a big difference.

    • @millicentsmallpenny5837
      @millicentsmallpenny5837 Рік тому

      Your trig class showed you all this material. You just werent ready for it, or didnt care. Generally at that age all people are typically thinking about is the hairy end of a belly

    • @studyeverydaywithcandrealx
      @studyeverydaywithcandrealx 10 місяців тому +1

      @@millicentsmallpenny5837 hell nah even tdy this material isnt shown in school, no way it was in the school system of the 60s

  • @hamieh1
    @hamieh1 3 роки тому +15

    Im 40 years old with MBA degree , i never knew what is sin and cos are until i watched your video. Why teachers are not like you in teaching . Very much appreciated the way you teach . Thanks 🌹🌹🌹

  • @vindonhadaway240
    @vindonhadaway240 Рік тому +10

    I never understood why we use these functions. Finally someone who can explain "the why of the trig functions." Excellent explaination. Impressive!

  • @seaddipper
    @seaddipper 2 роки тому +1

    I’m 72 years of age. I can only reiterate Halbert Thomas. “ I got this lecture totally” I’m addicted . Many thanks

  • @mrmanhunterthank8461
    @mrmanhunterthank8461 3 роки тому +14

    I thought I am learning math in the class in person with a teacher who is passionate what he is doing. Thank you so much for your time and passion!

  • @MrConradd
    @MrConradd 3 роки тому +3

    This teacher is awesome! My math teachers gave us tables, formulas, equations and said memorize them and use them! With very little explanation.
    Here's proof that a GOOD teacher is a country's greatest treasure!

  • @lyricass7810
    @lyricass7810 2 місяці тому +1

    Best video about trigonometry on entire UA-cam. Thanks for thr efforts sir.

  • @mutuakasoa9931
    @mutuakasoa9931 2 роки тому

    For 72 years I have been mouthing SINE& COSINE without knowing what they actually mean OR represent!!. Deep thanks for I am now happily enlightened.

  • @michaelvrijhoef4975
    @michaelvrijhoef4975 3 роки тому +32

    Small correction: If the hypothenuse is 5, that does not, by definition, mean the other two sides are 3 and 4. Which is what you seem to imply at around 5.20...... Let the hypothenuse be the radius of a unit circle, r=5. I can now rotate R and subsequently construct an infinite number of right triangles, hyp=5 but with varying lengths of the other two sides. A 3-4-5 triangle is just one of many possibilities.

    • @jakethemistakeRulez
      @jakethemistakeRulez 2 роки тому +6

      You can construct an infinite number of triangles. Only one of those is right with a hyp of five though.

    • @charlespartrick528
      @charlespartrick528 2 роки тому +4

      Only the 345 triangle will be a right triangle. Change any the lengths of the sides other than the radius and you don't have a right triangle.

    • @Tommekemertens
      @Tommekemertens 2 роки тому

      Thanx I was just scrolling down to see if anyone had any info on this, and here it is.

    • @UniqueBreakfastTaco
      @UniqueBreakfastTaco 2 роки тому

      😖

    • @jontyvandersluis3628
      @jontyvandersluis3628 2 роки тому +1

      @Ca Study sorry you are wrong and so is the teacher. The opposite could be 1 and the adjacent could be the square root of 24 for example. Use Pythagoras' Theorum. In a right angled triangle the hypotenuse squared = opposite squared + adjacent squared, so with a right-angled triangle with a hypotenuse of 5 can have any lengths of opposite and adjacent whose squares add up to 25. 3 and 4 may be the only 2 whole numbers whose squares add to 25 but there are an infinite number of non-integral numbers of values greater than 0 but less than 5

  • @johnstown2451
    @johnstown2451 3 роки тому +26

    Thank you!
    Old textbooks were simple and basic lessons, with a history lesson of why you were doing something. I’ve been buying early 1900’s university books off eBay.
    These new books have way too many pictures of panda bears and no reasoning for the lessons...

    • @MathAndScience
      @MathAndScience  3 роки тому +8

      Yes I agree!

    • @gusbey7723
      @gusbey7723 3 роки тому +2

      The practical application is really what people want to hear, very few have the love of theory. Keep up the good work.

    • @LANDSHARKK
      @LANDSHARKK 3 роки тому +1

      They call it common core

    • @mathfullyexplained
      @mathfullyexplained 3 роки тому +1

      Try my channel mathfullyexplained. Full unit on right triangle trigonometry plus more units

  • @nocawesirayi6255
    @nocawesirayi6255 7 місяців тому

    I'm 55years old lady I love maths very much even at school. I never think in my life I will understand maths the way I am now. Thank you so much for refreshing my mind even for others at my age. I enjoy this too much . May God bless you with many more years

  • @terryburton851
    @terryburton851 2 роки тому +1

    where was you when i needed you at school in 1952....brilliant thank you......

  • @fredy8321
    @fredy8321 3 роки тому +25

    This man is legend! I used to watch and learn from his calculus teachings and his videos helped me a lot while in college although he was young man that time, 13+ years ago. Thank you for teaching.

  • @Thebasicmaker
    @Thebasicmaker 3 роки тому +9

    Basic program to draw a circle (I learned it at 14!)
    1 cls 'clean the screen
    10 for n=1 to 360 'counts 360 degrees of the circle
    20 plot 320+100*sin(n), 200+100*cos(n) 'draw dots of the circle centered at coordinates 320 x pixels, 200 y pixels, and a radius of 100 pixels
    30 Next n
    40 end
    Do you want to try it? Download winape amstrad cpc emulator, type the program pressing enter or return at end of the lines and then typing run and typing enter or return again, you will see the circle being drawn dot by dot on the screen of your computer, want a filled circle ? Add 15 plot 320, 200 and change the 20 plot command in 20 draw using the command edit 20 command and [RETURN]

    • @martinkuliza
      @martinkuliza 3 роки тому

      1. CLS does not mean CLEAN the screen, it means CLEAR THE SCREEN
      Go to a CLI and type HELP , Look up CLS and you'll see the description CLEARS THE SCREEN
      2. What is the programming language.... BASIC or something like that ?

    • @Thebasicmaker
      @Thebasicmaker 3 роки тому

      @@martinkuliza sorry, you're right...I 'm Italia and I was confused by the similarity of the two words. It is locomotive basic, the basic used in the amstrad cpc 464 you can find a simulator called winape

    • @martinkuliza
      @martinkuliza 3 роки тому

      @@Thebasicmaker
      1. OK, No Problemo
      2. I've never heard of Locomotive BASIC. I'm from the old days of the commodore 64 and Atari Generation , i grew up on BASIC V2
      64K Ram system Ready :P
      that's why i recognized the BASIC code (not that it's hard to pick)
      3. Just for fun, I'm currently reverse engineering a ZILOG Z80 CPU . it's quite interesting
      i thought i'd mention it since you brought up the Amstrad
      4. I'll check out Winapd, thanks

  • @josephkingston9252
    @josephkingston9252 Рік тому

    I'm almost 70 years of age, and working for 5 different major oil companies early in life, the pipe trade in fitting requires knowing right angle trigonometry, this is a powerful math to know, it will reward you greatly to learn it.

  • @atirjilani
    @atirjilani 2 роки тому

    i am a 50 year old dad and i learned it again so i can sit with my child n explain it to him while we watched this video togather... thank you so much.

  • @fabblo5588
    @fabblo5588 3 роки тому +28

    when i was in the school, i really hated math. but when i'm watching this, my hate reverses becoming love feeling.

    • @omegalamda3145
      @omegalamda3145 3 роки тому +2

      Releases the fear factor memories releasing endomorphins. !Good for you

    • @mustafaali-wp2nu
      @mustafaali-wp2nu 3 роки тому

      I wish your English language hate reverses too :) jk

    • @thecarguys82
      @thecarguys82 3 роки тому +1

      @@mustafaali-wp2nu -_- bruh

  • @steveluke4779
    @steveluke4779 3 роки тому +3

    I also came across sines and cosines at school more than 70 years ago and I never understood what they were before now. Thank you for making it so clear.

    • @arjunyadav-kt5jr
      @arjunyadav-kt5jr Рік тому

      just out of curiosity! what made you come to math again?

  • @redundantpancake
    @redundantpancake Рік тому

    I've been a professional programmer for over 5 years. Software Development, so you generally don't use a lot of math like this. It's much more about collecting and showing data ina certain way.
    I've dabbled in game dev in my spare time and I can get pretty far. But a lot of it is looking up math functions for something, but not truly understanding what it does. It gets the job done a lot of the times, but I feel like I got stuck and not be able to progress and get my own answers to problems. Now I decided to go back to the beginning and truly try to understand vectors, trigonometry, dot product and cross product etc. I always get stuck on trigonometry because it's never truly explained what sine and cosine do (only how to calculate it). This video is incredible, especially understanding it and why its so powerful as a fundamental concept in game development.

  • @joseuzcategui5548
    @joseuzcategui5548 2 роки тому +8

    This is the best lesson on sine and cosine I have ever seen. I've been using them for years. I really wish that I had a teacher like you back in high school. Congratulations!
    Our world can definitely use more people like you. Keep up the outstanding work.

  • @CinKoDel
    @CinKoDel 3 роки тому +29

    This was a helpful refresher, your stick figures "third leg" gave me a giggle as well. Thanks!

    • @BradCozine
      @BradCozine 2 роки тому +5

      What's the angle of the dangle proportional to?

    • @josiahfadder
      @josiahfadder 2 роки тому +2

      @@BradCozine lol. I see what you did there

    • @avg5658
      @avg5658 2 роки тому +2

      I was scanning the comments just to see if anyone else noticed the tripod, too. ⚗️🤭😁😄

    • @Swegen7
      @Swegen7 11 місяців тому

      This man is a genius. He realizes the value of answering the age-old question every wise-ass kid has in school..." when will I ever need this?" It's shocking how many teachers never answered that question. It would have been so helpful to me personally, which is why I'm here now in my twilight years. It is only fitting that a hero of this caliber would be able to lift both feet off the ground at the same time. I wish him length... and girth.

  • @jamescullins2709
    @jamescullins2709 3 роки тому +19

    awesome explanation. Yes, I wish I had him in high school. You can hear the love of what he does in his voice.

  • @tareksma1
    @tareksma1 2 роки тому +1

    I finally got it. Thanks a lot. My teacher in gaza, palestine made me memorize it, and i didnt understand what i memorized and why I had to memorize it. Now I am 45 years old and I understood. Thanks a lot. You are the best teacher ever

  • @kenydemeza
    @kenydemeza 2 роки тому +1

    I really enjoyed science in school. I was good at it but Trig Stopped Me! I got an A+ Precalculus but I couldn’t move forward. I could never understand sin and cosin. After wasting so much time, it only took a 45 minutes video from someone I didn’t pay a cent to get it.
    Thank you so much sir.

  • @mariedillon1403
    @mariedillon1403 3 роки тому +78

    That's the best explanation of the sin cos ratio set up I ever heard...brilliant and thank you ☘️😊❤️

    • @MathAndScience
      @MathAndScience  3 роки тому +8

      Awesome thank you very much!

    • @mathfullyexplained
      @mathfullyexplained 3 роки тому +1

      Try my channel mathfullyexplained. Full unit on right triangle trigonometry plus more units

  • @lucaschueli984
    @lucaschueli984 3 роки тому +21

    Incredible! 60 years ago my math teacher was unable to make me understand sin&cos and I stuck with Pythagoras! Thank you so much for finally making me getting it at 75!🤗

  • @ayushchavan2741
    @ayushchavan2741 3 місяці тому

    The moment he explains how trig is applied in physics, my mind was blown. Its intriguing and spellbinding to understand how abstract looking mathematical concepts are applied in practical life.
    Thanks and thanks ❤.

  • @helenemaurer8623
    @helenemaurer8623 Рік тому

    I am 80 years and had a hard time with math .I will have to watch this a few times . Thank you. Wish I had you for a teacher when I was younger.

  • @Robert-qo8ld
    @Robert-qo8ld 3 роки тому +8

    To quote a previous question - -" when you start - if I am pushing with 5N
    and that force divides into 4 n and 3n - if I could extract those forces seperately I now have 7N total -"
    HOw can one get 7 N of force from 5 ?
    I would realy,realy like an answer

    • @mahathirmoon5010
      @mahathirmoon5010 3 роки тому +3

      Same question
      I am thinking it has something to do with pythagorus.

    • @Delphic1
      @Delphic1 3 роки тому +3

      My question too!

    • @genaroaraujo8080
      @genaroaraujo8080 3 роки тому +1

      I knew someone else would have noticed this also. Any answers yet?

    • @dospy1
      @dospy1 3 роки тому +4

      It is a bit more nuanced than that. What it effectively means is that if you push with 5N on that angle for lets say a distance of 500m (calculated diagonally), it is as if you pushed first horizontally with 4N for 400m and then vertically with 3N for 300m. This is the reason why the values cannot be "directly" added, because the split of 5N into 4N and 3N does not mean that the two resulted forces are applied for the same diatance as the original one.
      We could get the same results by calculating in time. The core idea is that the resulted forces are not applied in the exact same conditions, so that is why you cant just add them to get original force.

    • @emvill4520
      @emvill4520 3 роки тому +8

      His explanation mathematically is correct but the way he explained what is going on with regards to the forces is wrong or misleading.
      He should have used Joules... but let's go with this. The actual explanation is that the Hypotenuse is shorter compared to the Horizontal (Adjacent) and Vertical (Opposite) lines added together. So if you needed 5N to push the box through the length or distance of the Hypotenuse, you would need more force if you push the box Horizontally first and then go Vertical because the total length or distance traveled is LONGER. So going horizontal and then vertical would require 7N because of the longer distance the box would have to travel. I hope this makes sense.

  • @ynotspank1
    @ynotspank1 3 роки тому +8

    How I passed physics when I was in college years ago with a respectable grade, with zero understanding of the reasoning for sin and cosin is beyond me. Maybe because I just watched this video for the hell of it, just in case I ever needed this info, which I won't, but I know it and that's all that matters! Lol.

  • @onceuponatime365
    @onceuponatime365 2 роки тому

    finally I met the perfect math teacher in my entire life. I would like to see a book from beginner to advanced in maths. please write a book it would be a legacy for you and beneficial to the generations to come.

  • @mikehipparchusnewton7436
    @mikehipparchusnewton7436 2 роки тому

    This guy is a King at explaining math and science. (having an engineering degree instead of just being a "math professor" probably helps too. I was here just for a refresher.

  • @tonyjose5289
    @tonyjose5289 3 роки тому +12

    Loved the way you teach with so much energy and enthusiasm. However, its wrong and misleading to explain the force 5N splits to 4N and 3N. It could have been like 4N and 3N is needed to produce an effective 5 in the 3rd direction.

    • @paulhammond61
      @paulhammond61 3 роки тому +2

      Furthermore, it is NOT correct to say that if the hypotenuse is 5, the other two sides MUST
      be 3 and 4. They may be, but they could also be something else entirely, for example 2 and 4.582.

    • @Herlongian
      @Herlongian 3 роки тому

      @@paulhammond61 right triangle vs non right triangle?

    • @paulhammond61
      @paulhammond61 3 роки тому

      @@Herlongian David, all the above applies to right triangles only. If it is not a right triangle then there is no hypotenuse.

    • @Wanarunna
      @Wanarunna 3 роки тому

      @@Herlongian a right triangle with an hypotenuse of 5 could have other sides of length 1 and SQRT(24), or 2 and SQRT(21), The video is completely wrong to say that all right triangles with a hypotenuse of 5 have other sides of 3 and 4.

    • @simpleman283
      @simpleman283 2 роки тому

      This channel put out a video with some great information to help people get an understanding of what is going on in a 48 minute video. How long would this video be explaining every little nuance. Splitting N force proper and alternate right triangles with hypotenuse of 5. This is a starting place, and a HUGE help to most watching. You guys coming here critiquing this video have no video of your own.

  • @walterwhite9520
    @walterwhite9520 3 роки тому +4

    Once in class 9th I asked my government school math teacher where these words taken from ? From which language and what they literally means? He obviously didn't know. Felt little embarrassed and then shouted so much that I could never ask again. Thanks UA-cam that I am learning this in my 37th year.

  • @tomaaron6187
    @tomaaron6187 2 роки тому

    Phenomenal. I’m helping my 14 year old grandson with his trigonometry. He could do it but I could tell he didn’t know what he was ‘actually’ doing. I found this video and we followed it together…pausing so he could rephrase the points in his own words . Now he ‘gets’ what he is doing.
    I aced math throughout high school and second year Calculus in university. . Confession, I had no idea what I was doing until I had to apply it as a geophysicist. Your 48 minute lecture would have been invaluable when I was my grandson’s age… the better understanding, the more fascinating math becomes instead of a hurdle to get over. Most importantly, my grandson now has a positive towards his math class.
    Calculator? Ha! I learned using a slide rule and tables.

    • @MathAndScience
      @MathAndScience  2 роки тому

      Thank you so much. You are an awesome grandpa!

  • @DrMustafaArk
    @DrMustafaArk 5 місяців тому +2

    This lesson helps to explain why hip fractures occur mostly in women. Besides the osteoporosis, Femur hip angle is smaller in women, thus applying more force on the femoral neck. Thank you so much sir.

  • @barbufodor1186
    @barbufodor1186 3 роки тому +7

    Good Lecture. One observation: from the Physics point of view, when you decompose the 5N force into the horizontal and vertical components, these components need to have the same origin ... also common with the 5N force .This would also help when you use the projection on the y direction.

  • @kingdomfor1
    @kingdomfor1 3 роки тому +42

    I used cosine and tangent when I was building houses, to set out the framing for roof trusses, I wasn't interested in this at school, but when I became a builder , it came in very handy .

    • @Michel-yp8rd
      @Michel-yp8rd 3 роки тому +3

      Me too. As a 16 year old I never understood why I was learning this. Now I measure the length of walls roofs windows in architactical drawings and than the software makes a report of energy loss for the co2 problem in this world, every new house must have a report like this now.

    • @aumsath3620
      @aumsath3620 3 роки тому +1

      This practical knowledgeable shouod be transferred to people who are trying to learn this. Its people like you who must make some videos on this with demonstrations. Would be much easier and quick to assimilate the concepts.

    • @jeremykemp3782
      @jeremykemp3782 2 роки тому

      Same

  • @samuelg.kirstos1711
    @samuelg.kirstos1711 2 роки тому

    OMG I was just searching about sin and cosine for my little girl who is in secondary and she is so confused about it. instead I had a lecture for my self. wish I had it some 40 years back. we learnt the formulas and crammed it just to solve questions. knowing the real definition settles everything and last for ever. Master class. Thank you Sir. Salute.

  • @Jolynor
    @Jolynor 2 роки тому +21

    I’m in 8th grade and I want to learn early so I don’t stress when I’m older. I also code a lot so it’s helpful!

    • @generalpes9979
      @generalpes9979 2 роки тому +6

      Bruh good for you kid, when I was at 8th grade I wanted to learn Calculus so that I don't stress out learning. But turns out my knowledge is far left behind. Now I'm currently in 9th grade lol, currently discussing Trigonometry. Goodluck!

    • @jackhoff7880
      @jackhoff7880 Рік тому +3

      You'll forget more than you retain. Don't stress it pal

    • @Jolynor
      @Jolynor Рік тому +1

      @@jackhoff7880 thx

    • @keith726able
      @keith726able Рік тому +1

      No need to stress! The beauty of math is it is totally logical and consistent, unlike most of your other classes. All you have to do is learn the rules, do some homework, and you will succeed. I disagree with the comment that says you'll forget it all later. Once you learn math, you can devote your life to science or engineering and help humanity. I'm a 70+ year old chemical engineer and I've used this stuff my entire life, even in my woodworking hobbies, and so much else (I also code as a hobby).
      The magic of math is it develops the parts of your brain that think logically, instead of emotionally. You will see the world and the universe differently when that brain muscle has been developed and exercised.
      What do you use to code, Arduino?

    • @keith726able
      @keith726able Рік тому +1

      There's another GREAT utube math teacher: Eddie Woo. Please check out his videos on trig (and so much more math) - he's really great.

  • @whathasxgottodowithit3919.
    @whathasxgottodowithit3919. 3 роки тому +20

    I remember over 50 years ago we had books of tables sine & cosine, Logs & anti logs, no scientific calculators

    • @vara1499
      @vara1499 3 роки тому +1

      Yes, logarithmic tables. It had important formulae of mathematics and physics. We were not allowed to carry them in the examination hall. If we had to use, the invigilators would give us copies of the log.

    • @Gribbo9999
      @Gribbo9999 3 роки тому +5

      I am an engineer trained in the 60s and 70s. So I too remember the tables and the slide rule of course. Recently I tried to do a long division with pencil and paper and you know I couldn't remember how to do it! Took a while and some trial and error to relearn. Makes you really appreciate the power of a spreadsheets! Funnily enough using a slide rule's functions came back immediately and automatically last time I tried even after perhaps 40 years not touching one.
      .

    • @rusi6219
      @rusi6219 3 місяці тому

      We used both tables and calculators and it was amazing we were able to memorize so much of the tables by cross-referencing, this was in middle school

  • @rogerwright1168
    @rogerwright1168 3 роки тому +5

    We learned this as SOH-CAH-TOA. Sin is opposite over hypotenuse, cosine is adjacent over hypotenuse and tangent is opposite over adjacent.

  • @babarmirza6379
    @babarmirza6379 8 місяців тому

    By God, I never saw a this kind of teacher before , lots of love from Pakistan
    Bold and concept way of teaching,SIR. Hatttsss off.

  • @fromexoplanet21
    @fromexoplanet21 2 роки тому +53

    Amazing content every single second was full of important information and it was so well explained!! Thank you for uploading these lectures for free💖

  • @Afrocanuk
    @Afrocanuk 3 роки тому +6

    When I took trigonometry in school, I trained myself to always say "Sine ANGLE theta & Cosine ANGLE theta." Never just Sine theta & Cosine theta.

  • @juansulca9037
    @juansulca9037 3 роки тому +9

    I learned with this lesson more than the whole time that I studied in high school, even in the College. The teacher has a great examples to show how its would be easier to student figure it out, for me it was that I almost see the vector was moving.

    • @adhil8918
      @adhil8918 3 роки тому

      Can you teach it???

    • @adhil8918
      @adhil8918 3 роки тому

      Can you teach me please???

    • @rf_carlsen
      @rf_carlsen 3 роки тому

      Juan Sulca right ? I wish i had UA-cam in my time 😏

  • @ciscoben6430
    @ciscoben6430 2 місяці тому

    Love watching you from morocco .
    You just saved my life to make my son understand sin cos tang .

  • @boblibala9915
    @boblibala9915 Рік тому

    I have watched so many people here teaching sciences but but the way this guys explains these chapters is awesome, way aboooooove others. His accent is very easy for me, and the formulas other teachers come and throw on the blackboard this guy explains them from their beginning and how they came to life. I simply loooooove his methods. Thumbs up, man!

  • @jesse7603
    @jesse7603 3 роки тому +10

    After this video, my hair and beard turned white and I had a stone tablet in each arm. One called sine and the other called cosine. Amen.

  • @johngirolamo8221
    @johngirolamo8221 3 роки тому +21

    If only you were my instructor back at school, I may have enjoyed and eventually got a passing grade in math! I love all your videos! I never got to trigonometry, but you make it understandable! I love it! Thank you!

  • @JohnSmith-do1pj
    @JohnSmith-do1pj 2 роки тому

    When I went to school, the only tools we had for these studies, were a slide rule and log book. The slide rule I used to draw straight lines with, and the log book was just a schoolbag filler, as I had NO idea of what I was meant to be studying. This is SOOOO much easier than what was ever explained to me, and the calculator makes things so much more simple. Cheers from Downunder!

  • @jaydeest
    @jaydeest Рік тому

    Some teachers just have this special talent about them where they can break down anything and make you understand while keeping you engaged. This gentleman has that special talent. Now if he can teach me how to build a time machine.

  • @safinabard9394
    @safinabard9394 3 роки тому +5

    I am speechless of what you have done. I really appreciate and it it was the best way of understanding the sine and cosine, which I have never seen it before. Tanks for this great job.

  • @martinkuliza
    @martinkuliza 3 роки тому +7

    Ok... I HAVE A QUESTION
    I understand that HYPOTHENUSE is the WHOLE, the 100% if you will
    I understand that the Cosine and Sine are a FRACTION of the Hypothenuse or more specifically A RATIO in both X direction and Y direction RELATIVE TO HYP
    ok... so if X = 0.8 and Y =0.6
    so... X means 80% of the force of THE HYP is in X
    Y must therefore before 20% because hyp Is a representation of a whole
    hence if it was a straight line it would be 1.0
    How do we conclude that 80% + 60% = 100% ?

    • @martinkuliza
      @martinkuliza 3 роки тому

      @NRG
      you didn't answer my question
      the question was...
      How do we conclude that 80% + 60% = 100% ?

    • @martinkuliza
      @martinkuliza 3 роки тому

      @NRG
      oh.. i see
      i interpreted it the wrong way.... my bad

    • @winxkorean
      @winxkorean 3 роки тому +1

      You're dealing with a right triangle. So your equation *hypothenuse = x + y* ( from your *100% = 80% + 60%* ) is wrong. A hypothenuse is never the sum of the opposite and the adjacent. It has to be *hypothenuse² = x² + y²* as in the pythagorean theorem *c² = a² + b²* , so its *100² = 80² + 60²* or *1² = 0.8² + 0.6²*

    • @winxkorean
      @winxkorean 3 роки тому +1

      @NRG When you walk 5meters on a hill slanted at 36.87°, you are horizontally 4 meters away from where you started going up and are 3 meters high from the ground. This diagonal movement doesn't mean you have walked 4 meters plus 3 meters. You WALKED UP 5 METERS at an angle of 36.87°.
      In the same way, if you walk 100 meters on thay same hill slanted at 36.87°, you are horizontally 80 meters away from your departing point, and 60 meters vertically up.
      You are thinking that the "total force" mentionned means literally the toral sum of two different numbers. What he implies by the "total" is, if that digonal line at an angle of 36.87 is 1unit (which is 1.00 o read 100 PERCENT) than the vertical line is 0.6 (which can be also read as 60%) and your horizontal line is always 0.8 (or 80%). Or put it differently, if your diagonal is a certain number, your vertical line is 60% of that number and the horizontal 80%.
      I'm not usually good at explaining math but I hope this helped.

    • @martinkuliza
      @martinkuliza 3 роки тому

      @@winxkorean
      well... that certainly makes a lot more sense.
      thanks

  • @daveworkman8845
    @daveworkman8845 2 роки тому

    I'm 74 years old. Hobby is woodworking and I still use trig, but this was the first time that I truly realized the "why" of those numbers. I like his description as the chopping function.

  • @hoanvu9922
    @hoanvu9922 2 роки тому +1

    This lesson should be the very first subject on all math subject text books. All teacher should learn this too. Great Mind think simple.

  • @shessoperfecrblahblahblah
    @shessoperfecrblahblahblah 3 роки тому +3

    explained flawlessly, im not even halfway into the video and this is starting to make sense, thank you so much!

  • @KD-cb2kt
    @KD-cb2kt 3 роки тому +3

    I am so glad that I found him, he is better than all math teachers that i had! you saved me thanks! keep doing what are you doing!

  • @chriswhalen8684
    @chriswhalen8684 2 роки тому +1

    “When the student is ready the teacher arrives”. I’m 68 and finally am ready. Thank you teacher!

  • @riazmkhan
    @riazmkhan 2 роки тому

    Absolute genius as a teacher....Every student should insist that their teacher is as good as this... Me? I'm simply thankful for this.

  • @THillick
    @THillick 2 роки тому +15

    “This is what they’re for….” Should be the second sentence spoken by every teacher of every course following the name of the course.

    • @4everThoughtful
      @4everThoughtful 2 роки тому

      I agree 100%. The shove in a bunch of formulas without a clue of telling you the "why" or the "what's the job" of them.

  • @paulwharton1850
    @paulwharton1850 3 роки тому +7

    This guy is brilliant - I wish I had him as a teacher - Now I actually understand what the hell Sine & Cosine are - I've seen them on calculators for years !
    Many thanks.....all the way from London.

  • @robertojo1103
    @robertojo1103 2 роки тому

    I had a hell of a time in my university calculus class. I wish I knew this concept in high school, it would have changed my academic life. I am 75 years old now and I can scratch this bucket item. Thank you!

  • @alejandra6967
    @alejandra6967 9 місяців тому +1

    Legend!! I wish I had you as my teacher in High School

  • @arshidayoub2355
    @arshidayoub2355 2 роки тому +3

    I have always had hatred for mathematics. But your way of teaching and making us understand the basic fundamentals is absolutely outstanding. If you were my teacher then my life would have been a different today. Thanks

  • @EyeIn_The_Sky
    @EyeIn_The_Sky 3 роки тому +3

    AMAZING, Thank you!!. I have tried to tackle this area to give me a platform to go onto other things like Algebra and Calculus but always struggled and avoided Sin and Cosin as it seemed so abstract and a memory game. I would have been much further along over the years if I had seen this explanation the "what it actually is/does/used for. My brain just refuses to accept remembering stuff that it does not know the use for or aim of it/progression. Also, can I suggest you move to the transparent board to write on (where you are facing us) rather than having your back to us blocking the board (some other channels use it) as I find myself having to keep skipping back and breaking the flow of your lecture to see what was on the left side of your board that you are blocking.

  • @ahmed_mahrouky
    @ahmed_mahrouky 3 роки тому

    I was excellent in math but was saving as a computer , now am a 42 years doctor , finally I understood and I am veery happy . thank you very much professor

  • @timspooner59
    @timspooner59 2 роки тому

    Very clear thank u. I am 68. I had a very similar math teacher who got 99% of students passed A level maths. Best teacher ever

  • @robertochavez8196
    @robertochavez8196 3 роки тому +3

    At foothill college, I had great teacher . Just as great as this man; God bless them!!!!

  • @ajaz3384
    @ajaz3384 3 роки тому +6

    Question: how do you explain the sum of component forces is bigger than the total force ?

  • @coolstar3971
    @coolstar3971 29 днів тому +1

    I got a solution to solve my problem. Fabulous effort Thank you sir.

  • @Mike62501
    @Mike62501 2 роки тому

    Me Too!
    I think I can remember this now I will watch at least 1 more time. At 72 I found other ways around not knowing with help from many engineers (thanks to many) in my life. Your students don’t know how lucky they are to have you as a teacher! Mike