Evaluate for sine cosine and tangent using reference angles

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  • Опубліковано 12 гру 2024

КОМЕНТАРІ • 71

  • @brianmclogan
    @brianmclogan  11 років тому +40

    thank you, happy to help

  • @kylegorny9479
    @kylegorny9479 6 років тому +52

    Thank you so much for making all of these videos I'm taking Pre-Cal right now and honestly your videos are the reason why I have an A in the class and don't get super lost in the sauce. Thanks again you're the best!!

    • @brianmclogan
      @brianmclogan  6 років тому +3

      awesome! Keep it up Kyle!

    • @kjutved4678
      @kjutved4678 5 років тому +1

      I’m studying rn and these videos are saving me from failing

  • @masawarelahi1604
    @masawarelahi1604 6 років тому +95

    Took 4 minutes to explain what my teacher couldn't in 3 hours

  • @parkerscurria6622
    @parkerscurria6622 5 років тому +4

    Thank you so much for EVERY SINGLE video you have made. You have helped me so much in my trig college course and I can't thank you enough. I wish I had you as a teacher!!

  • @brianmclogan
    @brianmclogan  11 років тому +2

    you are very welcome!

  • @bluereino
    @bluereino 5 років тому +13

    I am having to search online for help because I have one of those math teachers who give you notes on one thing and not everything and when you get to the homework the problems are different or different types. It is really frustrating and wastes so much time that I could've spent doing other homework.

  • @joshhansen6880
    @joshhansen6880 8 років тому +1

    I totally didn't understand this concept at all until this video. Bravo!

    • @brianmclogan
      @brianmclogan  8 років тому

      +Josh Hansen happy to assist you!

  • @autumnwilomovsky5129
    @autumnwilomovsky5129 5 років тому

    You fucking rock, dude! Taking precal this semester and every time i have a doubt, i come to your channel and you set my mind at ease. Also, you sound so much nicer when teenagers aren't around lmao.

  • @laurag6172
    @laurag6172 7 років тому +1

    Lovely! My teacher didn't go over this part of our homework during our note session, but you helped me out big time! Thanks!

  • @rimishasrivastava8740
    @rimishasrivastava8740 4 роки тому

    ur videos r saving my life

  • @pabloperro4458
    @pabloperro4458 3 роки тому

    Thank you for these videos man you are helping me get through my pre calc class you are awesome

  • @sarahreyes2892
    @sarahreyes2892 6 років тому +1

    I love how you teach!!!!!!!!!!!!!!!!!!!!!!!!

  • @husky8652
    @husky8652 4 роки тому

    just use the original degree to see which quadrant it sits and the signs. for example cos200 , its located third quadrant which sin -, cos - and tan +. so we know the sign and then just do the rest

  • @elifmutafoglu
    @elifmutafoglu 5 років тому +3

    If my college had you as a professor i would just wait to add your class do you see how rare is this for a college student

  • @extraoridanaryexplorations1479
    @extraoridanaryexplorations1479 2 роки тому

    Your trig is wonderful

  • @eslamkagigi4835
    @eslamkagigi4835 6 років тому +4

    Thank u so much best explanation
    Do u have any other videos to help alevel students with Maths ???

    • @brianmclogan
      @brianmclogan  6 років тому

      not familar with your curriculum but I do have a lot of videos, some basic some advanced

    • @eslamkagigi4835
      @eslamkagigi4835 6 років тому

      Brian McLogan edexcel

  • @gunnertyme7414
    @gunnertyme7414 3 роки тому +1

    This just saved me

  • @michaellearnsgregori7333
    @michaellearnsgregori7333 2 роки тому

    Thanks a lot sir!

  • @jannatulnyeemratul6039
    @jannatulnyeemratul6039 5 років тому +1

    Sir,Why is sin of the reference angle equal to sin of the original angle?I would be very grateful if you answer sir.

  • @nssjsjnssjsj9619
    @nssjsjnssjsj9619 9 місяців тому

    Thanks a lot

  • @casypp3710
    @casypp3710 4 роки тому +3

    Wait how did you find the coordinates at first? That’s the main problem i have that I cannot find the coordinates of x and y plz explain

  • @celinecapiral5423
    @celinecapiral5423 9 років тому

    This is awesome! Thanks!

    • @brianmclogan
      @brianmclogan  9 років тому

      Celine Capiral you are very welcome! happy to be able to help

  • @ANONYMOUS-ud8fl
    @ANONYMOUS-ud8fl 3 роки тому

    Thanks!

  • @Priyanka-lq9ev
    @Priyanka-lq9ev 3 роки тому

    Thank u 😀😀

  • @stephaniev4796
    @stephaniev4796 7 років тому +4

    How are you finding or how would i know that 60 degrees (x,y) = (1/2, pi*/2 ) how do you find the x and y ? Do you have a video on explaining that ? Thank you !! I passed my last exam cause of you (log test)

    • @brianmclogan
      @brianmclogan  7 років тому

      awesome! yes I do it there are a couple of videos explaining that, it is all about similar triangles on the unit circle. Here is the playlist ua-cam.com/play/PL0G-Nd0V5ZMqaymBMKRLmm-VvKIEQhyQT.html

    • @legendaryhero6695
      @legendaryhero6695 Рік тому

      he found it by the unit circle

  • @shenelldixon3814
    @shenelldixon3814 11 років тому

    nice.well explained

  • @adityatiwary3144
    @adityatiwary3144 7 років тому

    Awesome explanation...

  • @vivianruiz2733
    @vivianruiz2733 11 років тому

    Thanks so much!

  • @Joshua-wg5lt
    @Joshua-wg5lt 5 років тому

    what class are you teaching this to? I'm feeling anxiety about a class I'm going into and I want to know if I need to know this method well

  • @mewpaa
    @mewpaa 5 років тому

    THANK YOU SO MUCH!!! i actually feel some what smart now hahaha, wish my school taught it this way!!!!

  • @vivaldikonzsmith7291
    @vivaldikonzsmith7291 8 років тому

    Thank You

  • @martinromero5156
    @martinromero5156 7 років тому +1

    Is it possible to find the cos and sin using just an angle? Example 46 degrees

    • @brianmclogan
      @brianmclogan  7 років тому +1

      using special right triangles we can only find the exact value of sine for angles 30,45,60 and angles based off those values(multiples, add and subtract). For any other angle we will have to approximate with a calculator

    • @martinromero7469
      @martinromero7469 7 років тому

      Brian McLogan thanks for the feedback I really appreciate it.
      Last question, this I based of unit circle. How does changing the radius effect the cos and sin. Ex.
      120 degree angle with 20 radius?

    • @brianmclogan
      @brianmclogan  7 років тому

      the points would be the exact same as the ratios do not change, however you would multiple each answer by 20 as that would be your multiplier.

  • @krishnashukla644
    @krishnashukla644 5 років тому +1

    Why root 3

  • @javiersalmeron3186
    @javiersalmeron3186 8 років тому

    What is the reference angle?

  • @mandzgibz2268
    @mandzgibz2268 8 років тому

    why are the coordinates in between quadrant 1: 1/2 and square root of 3/2? forgive me. I'm still new at this.

    • @brianmclogan
      @brianmclogan  8 років тому

      +assdafegkush hard to describe in a comment search my channel for how to create the unit circle or where does the unit circle come from.

    • @brianmclogan
      @brianmclogan  8 років тому

      +assdafegkush short form it's all about special right triangles

    • @mandzgibz2268
      @mandzgibz2268 8 років тому

      Mr. McLogan's Math Channel thanks for the help!

  • @sonofjesus1464
    @sonofjesus1464 7 років тому

    I am having such a hard time, actually the hardest in my entire algebra history trying to find what the radian measures o all angles who's sine is -0.9 using the calculate and then the unit circle. The unit circle is crazy difficult but I have to find why the radian measures are -1.12 + 2(pi)n and 4.26 + 2(pi)n. I HATE NOT GETTING HOW TO DO THIS o:;;;

    • @brianmclogan
      @brianmclogan  7 років тому

      ua-cam.com/play/PL0G-Nd0V5ZMpqCJQreDI0Q7ibZ-q8pQ8v.html
      ua-cam.com/play/PL0G-Nd0V5ZMqaymBMKRLmm-VvKIEQhyQT.html
      Here are two playlists that might help you out. The first describes angles especially radians vs degrees where as the second talks more about the unit circle. It takes time for this info to sink in. Do not worry it will eventually. Keep up the hard work

    • @sonofjesus1464
      @sonofjesus1464 7 років тому

      Thank you so much wise teacher :D

  • @randydiebold325
    @randydiebold325 6 років тому

    this tells me nothing.. if i have and angle 23 degrees how do I evaluate for sine. show that. not for angles that we are supposed to memorize.

    • @brianmclogan
      @brianmclogan  6 років тому +1

      um calculator

    • @randydiebold325
      @randydiebold325 6 років тому

      so one day a calculator magically fell from the sky and that's how humanity learned about trig functions?

    • @randydiebold325
      @randydiebold325 6 років тому

      Look thank you for putting up videos helping people. I'm sorry. I'm just frustrated. I've been looking for a couple of days now online every time I look up up how to evaluate trig functions without using a calculator i keep getting videos about 30 45 60 angles. There was a time before calculators and I would just like to know how to do it without one. I think understanding that process would beneficial to understanding whats going on. Do you have any reference you can give me or some different keywords I should use that might come up in a high math? I'm sorry for getting upset. I would appreciate any information you could share. Thank you.

    • @brianmclogan
      @brianmclogan  6 років тому

      so back in the day , they still didn't manually evaluate those trig functions they had reference charts, yes there is a mathematical way to do it but not sure how. The fact we have been using charts and calculators for so long for those types of angles should say something about the complexity of evaluating for not 30-45-60 angles

  • @harmeetdhillon7879
    @harmeetdhillon7879 3 роки тому

    If you took sin( 270+30)

  • @ethantran1886
    @ethantran1886 5 років тому

    Lmao... 60 degree in unit circle is 1/3 of pie not 1/2 of pie

  • @_ElChilango_
    @_ElChilango_ 4 роки тому

    420 nice

  • @rickysalani5668
    @rickysalani5668 6 років тому

    Going to quick. Slow down, we are all not as smart as you -_-