Easy Trick to Find Exact values for sin cos tan.

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  • เผยแพร่เมื่อ 13 ธ.ค. 2024

ความคิดเห็น • 578

  • @RelearnMath
    @RelearnMath  6 ปีที่แล้ว +3

    FOR AN ANIMATED VERSION OF THIS VIDEO PLEASE CHECK OUT
    th-cam.com/video/_KaZWu5OKag/w-d-xo.html

  • @kristianbrasel
    @kristianbrasel 10 ปีที่แล้ว +111

    The music in the background is really annoying when you are trying to learn something.

    • @Jburtonsemo1
      @Jburtonsemo1 10 ปีที่แล้ว +8

      basically what Kristian Brasel is saying..."hey guy taking the time to make a nice tutorial to help others for free. I feel like complaining" =/ Kuddos for Sick Puppies in the background :)

    • @kristianbrasel
      @kristianbrasel 10 ปีที่แล้ว +9

      Justin Burton it would be a nice tutorial if there wasnt music blaring in the background. it makes it hard to focus. I am just trying to give some constructive criticizm. quite a few people agreed with me.

    • @marcobarraza5343
      @marcobarraza5343 10 ปีที่แล้ว +3

      kristian brasel Yeah but he is giving his time to us so i really did not mind. he is better than my teacher thats for sure

    • @kristianbrasel
      @kristianbrasel 10 ปีที่แล้ว +2

      im not trying to troll the guy, just let him know. he could have just as easily made the video with no music, and if he makes another one (which people on youtube tend to do) than maybe he will take the criticism and make a much more pleasant video next time.
      his video got a good amount of views, people make decent money off of youtube, if that is his intention than i would think he would welcome any constructive criticism people have to offer.
      plus, even if he made the video just to help other people than you would think he would actually care to know how he could make it better.
      you guys are acting like i just insulted the guy, if you cant take criticism than you shouldnt be on youtube.

    • @BrandonSLockey
      @BrandonSLockey 9 ปีที่แล้ว

      kristian brasel i found it distracting at first but when he started teaching the trick I didn't notice it anymore.

  • @RelearnMath
    @RelearnMath  9 ปีที่แล้ว +39

    Made a new video that explains the trick in 2 minutes + no background music!

    • @ShifterPEE
      @ShifterPEE 9 ปีที่แล้ว

      how do you calculate cos (A/2) ,given sin A= -3/5 ?

    • @ShifterPEE
      @ShifterPEE 9 ปีที่แล้ว

      how do you calculate cos (A/2) ,given sin A= -3/5 ?

    • @ShifterPEE
      @ShifterPEE 9 ปีที่แล้ว

      how do you calculate cos (A/2) ,given sin A= -3/5 ?

    • @RelearnMath
      @RelearnMath  9 ปีที่แล้ว

      +Pee Wu Jian Algebra, just treat A/2 as a different variable, call it t, now t = A/2 or A = 2t.

    • @dorotadodulek7953
      @dorotadodulek7953 8 ปีที่แล้ว +3

      and u didn't give the link...how helpful!

  • @DrakesKAKES
    @DrakesKAKES 12 ปีที่แล้ว +2

    No joke, I have a midterm and I've missed so many classes, and haven't taken trig in 10 years. I've been teaching myself online for the exam for 5+ hours. This 6 minutes video did more for me than ANYTHING I've looked out. You're seriously the man.

  • @125ponygirl
    @125ponygirl 10 ปีที่แล้ว +3

    Omg! Thank you so much! Unlike every other tutorial I've seen, yours was the simplest and clearest! Everyone else's was just so confusing ! Yours is the best. Though your music is a bit distracting but it saved my life. I should have noticed this sooner!

  • @tccottrell82
    @tccottrell82 10 ปีที่แล้ว +144

    turn the music off please

    • @scitwi9164
      @scitwi9164 7 ปีที่แล้ว

      True. Background music should support the presentation, not distract it :P

    • @sahdevrajak3537
      @sahdevrajak3537 7 ปีที่แล้ว

      Really yar

    • @RelearnMath
      @RelearnMath  6 ปีที่แล้ว

      Sorry! I animated the video and made it better!

  • @Comment0136
    @Comment0136 11 ปีที่แล้ว +2

    Use the concept of reference angles; since 330's in quadrant 4, you subtract it from 360. (360-330 = 30). Use the sin/cos values of 30 but change the signs and since the angle is in QIV then it's y-values (sin) are negative. Sin30 is 1/2 and sin 330 is -1/2. The same goes for other reference angles

  • @s9h8o7
    @s9h8o7 11 ปีที่แล้ว +20

    I CAN HONESTLY CANT THANK YOU ENOUGH SIR! MASSIVE RESPECT FOR U! U SAVED MY LIFE

    • @stanciularisa6174
      @stanciularisa6174 11 ปีที่แล้ว

      lol how saved ur life?:-))

    • @RelearnMath
      @RelearnMath  10 ปีที่แล้ว +2

      LOL

    • @rakshaprabhu3738
      @rakshaprabhu3738 10 ปีที่แล้ว +3

      Stanciu Larisa you will understand how....... when its ur test tomorrow and u cant even remember anything cause its so complicated

  • @saltyppancakes717
    @saltyppancakes717 2 ปีที่แล้ว +1

    This guy is a bloody genius. I hit a roadblock weeks ago and this guy fixed it in like 30 seconds. Well done!

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @kiojose Sorry for the lack of reply but as a college student I don't have a lot of time in my hands, but to answer your question there are several ways to figure it out, but the easiest and using the "trick" above would have to be using your imagination, first subtract increments of 360 to 1200 until we get it to a value below 360. So if you subtract 360 3 times your left with 120 degrees. Then we picture the unit circle in our mind, we know that in quadrant 2(between 90 and 180) the value 120

  • @TR_Cabaroc
    @TR_Cabaroc 11 ปีที่แล้ว +6

    I actually clapped my hands after watching the video! congratulations for your first video :)

  • @jenisinjapan
    @jenisinjapan 9 ปีที่แล้ว +6

    For *bigger* numbers, (120°, 135°, 150°, 180°), the trick still works, but *for sin*, for every angle, instead of 0, 1, 2, 3, 4 like in the video, count down from 4 to 3 to 2 to 1 back to 0.
    So, if sin90 is sqrt4/2, sin120 will be sqrt3/2, sin135 = sqrt2/2.... so on.
    *For cos*, you have to count up, so from 4, 3, 2, 1, 0 in the video, for every angle, it goes from 1 to 2 to 3 to 4, but add negative (-) in front.
    So say cos90 = 0, then cos120 = -sqrt1/2, or -1/2, cos135 = -sqrt2/2, cos150 = -sqrt3/2.... so on.

    • @RelearnMath
      @RelearnMath  9 ปีที่แล้ว

      Jenalene Santelices Yes that is correct, I explain this in another video that I have.

    • @youssefhabeib7606
      @youssefhabeib7606 9 ปีที่แล้ว

      +RelearnMath so does that go for the angles after that too. like 210, 225, 240, etc...

  • @cassandrad.2981
    @cassandrad.2981 10 ปีที่แล้ว +3

    You have no idea how much this video helped me. I did great on my trigonometry exam because of this. Thank you for sharing!

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @comeon7894 I should have explained reference angles in the video because I get a lot of these questions on my inbox lol, ok for sin(240) we first find the reference angle, 240 is the same as 60 degrees except that its in quadrant 3(picture the unit circleit in your head ), so we use the trick for sin(60)and we get [sqrt3/2] but since sine is negative in quadrant 3 that answer is [-sqrt3/2]

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @GeneVarsity Im not sure what your asking but you find tangent by using the relationship between sin and cos, since we know that tan= sin/cos

  • @chrislai6691
    @chrislai6691 5 ปีที่แล้ว +3

    apart from the low quality of the video and that ear-stabbing background music
    the trick is really helpful
    big fat thank to you dude

    • @RelearnMath
      @RelearnMath  5 ปีที่แล้ว

      I have a version that’s animated and cleaner

  • @av8706
    @av8706 12 ปีที่แล้ว

    holy, this is a life saver...up to this point I only knew how to get common angles between 30 and 60 without memorizing stuff! Now I know how to get 90 and 0 as well !!! And I just realized I can get 180 by negating the exact values!!! Thanks man.

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    I had about 3 other ones that needed editing but my computer messed up and I just recently bought a new one :/, anyway I will get back to making videos ASAP when I finish midterms,

  • @A-Black-Chair
    @A-Black-Chair 10 ปีที่แล้ว +14

    you sir , have just saved my life

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว +2

    @dhill89 Lol I kept the music on so that my next door roomates wouldn't think im crazy talking to myself.

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @kiojose exists which is the same as 1200 right?, after that we know that coming from the right(where the 90 is) toward the 180,120 degrees is 30 degrees more and coming from the left is 60 degrees more, so from the left (180) we know that its 60 degrees, so we take tan 60 and we know its sqrt(3),but since its in quadrant 2, we know that its going to be negative since only the sin values are positive :). I hope you understood my long explanation lol ill try to explain it better in a video using

  • @ilovescupcakes
    @ilovescupcakes 12 ปีที่แล้ว

    If you use a ti-84 Plus just hit math then Frac to convert a decimal into a fraction. To make every answer come out as a fraction hit mode, go to the second page and where it says answers choose FRAC. I think it should be the same on other 84's and 83's. I know its the same on the TI-84 Plus Silver Edition.

  • @RelearnMath
    @RelearnMath  11 ปีที่แล้ว

    Thanks Carissa, and actually this video was a one shot vid, I shot it from my phone and uploaded it directly, didn't edit or anything lol.

  • @RelearnMath
    @RelearnMath  9 ปีที่แล้ว

    What level of Math are most of you taking? Thinking about making a series for a specific Math class, otherwise I will upload transmission line theory videos haha.

    • @sidl8698
      @sidl8698 9 ปีที่แล้ว +1

      +RelearnMath IM in Trig Honors for high school. Thanks for the simple method really helped, especially knowing that my teacher is to stuck to teach up lol. These lessons would really help me out!

  • @RelearnMath
    @RelearnMath  8 ปีที่แล้ว +8

    If you want to know how to get exact values for larger angles/radians check out my other video where I explain
    th-cam.com/video/lpss5t7Vx44/w-d-xo.html

    • @AdityaX2703
      @AdityaX2703 8 ปีที่แล้ว

      can you make a video regarding to find tan,cos,sin of no. like 23,45,67,46 irregular and exact

    • @RelearnMath
      @RelearnMath  8 ปีที่แล้ว

      aditya singh yes , video is coming soon!

    • @AdityaX2703
      @AdityaX2703 8 ปีที่แล้ว

      thanks for your grear job there is no one who can teach me I am an orphan thanks for your help

  • @boogiemanspud
    @boogiemanspud 8 ปีที่แล้ว +1

    Thanks, you saved my butt. Taking a test for a job promotion/bid and I couldn't seem to memorize the chart. This makes much more sense than memorizing a chart.

  • @billyboy554
    @billyboy554 12 ปีที่แล้ว

    This helped SO much. My exam board don't want the values rationalised, but with this method, only sin45 and cos45 need to be rationalised and it is REALLY easy.

  • @RelearnMath
    @RelearnMath  11 ปีที่แล้ว

    well sometimes teachers follow a strict curriculum and if you are thinking of majoring in any STEM major then it's wise if you memorize them

  • @nukima11
    @nukima11 10 ปีที่แล้ว +2

    You explain it better than the teachers. All I could find was "This is what it is because it is." None of them ever really "Explain it." Good job, dude.

    • @nukima11
      @nukima11 10 ปีที่แล้ว

      Oh yeah, BTW, MOAR!!!

  • @TheDreamclubMurders
    @TheDreamclubMurders 12 ปีที่แล้ว

    You just made such a complete foreign subject to me make so much sense!! Thank You so much! :) This will definitely help me in the long run

  • @Stelnice
    @Stelnice 10 ปีที่แล้ว

    wish I had seen this before taking any entrance exams....YOU ARE SO AMAZING! NEVER HEARD ABOUT THIS BEFORE. please upload more tricks that would make our lives easier.

    • @peppapig7729
      @peppapig7729 4 ปีที่แล้ว

      Hello it’s peppy from the future

    • @peppapig7729
      @peppapig7729 4 ปีที่แล้ว

      It’s 2020 now 😘

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @kiojose radians as well to get another perspective, i hope i didnt bore you with the essay lol^

  • @tonymarelich7391
    @tonymarelich7391 10 ปีที่แล้ว

    It's the simple stuff that often helps the most. Loved this technique. Thanks very much for the video.

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @invaderaf tan150= -tan(180-150)=-tan30= -sin(30)/cos(30) = (-1/2)/sqrt3/2= -1/sqrt3 = -sqrt3/3

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    don't worry i can relate, I've been out for the same amount of time and its hard to remember the old stuff , well i don't know what other stuff are in the ASVAB but i heard its not that difficult, and ive been really busy lately :( i will try to get back to youtube videos as soon as possible and just a tip if all else fails when factoring always go to the quadratic formule :) goodluck!!

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    I do have a bunch of stuff, but I just haven't had the time to edit them and put them up :(, what specifically do you need help in?

  • @maksuree
    @maksuree 10 ปีที่แล้ว +4

    if you can use a calculator but your stuck with a crippled Board-approved POS, just enter the question (ie sin45), square it (remember to press the S 》D button), and then root of the top and bottom numbers.

    • @woopwoopkaboom1
      @woopwoopkaboom1 10 ปีที่แล้ว

      love u

    • @michoian
      @michoian 7 ปีที่แล้ว

      Gary what is the S >>D button?

    • @maksuree
      @maksuree 7 ปีที่แล้ว

      I can't remember, I finished high school a while ago

    • @rachelk1300
      @rachelk1300 6 ปีที่แล้ว

      Thank you!!! this saved my life

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    You are absolutely right, however for a student who just needs to pass trig this can be very helpful.

  • @tavito0503
    @tavito0503 11 ปีที่แล้ว

    Dude this video is going to help me a lot with my trig class! keep it going!

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    yes sorry no music next time

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @Octayne93 Its a TI-XS MultiView, I got it at target for like 10$

  • @JohnDoe-xb2wq
    @JohnDoe-xb2wq 8 ปีที่แล้ว

    You sir just saved my life. Definitely subscribed.

  • @username7340
    @username7340 12 ปีที่แล้ว

    YOU JUST EXPLAINED WHAT MY COLLEGE PROFESSOR COULD NOT! THANK YOU!!!!!!!!!!!!!!!!!

  • @HipposCanFlyy
    @HipposCanFlyy 10 ปีที่แล้ว +2

    how did you get your calculator to show the value in fraction form with root in it?

    • @ritesh6487
      @ritesh6487 10 ปีที่แล้ว

      yes what you said is right because sin30 when you press in calculator it shows 0.5 but not 1over2

    • @ritesh6487
      @ritesh6487 10 ปีที่แล้ว

      but on calculator 1/2 gives 0.5 sis

  • @angellocorvalan7236
    @angellocorvalan7236 10 ปีที่แล้ว

    You helped so much! This method is genius! I would've never been able to memorize the 30,60,90 and 45,45,90 triangles! You don't need to even know them without this amazing method! Thank you!

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @MELLOGURLY No problem and you welcome, spread the word :).

  • @hunteredge3663
    @hunteredge3663 11 ปีที่แล้ว

    holy balls dude. You're over powered and a GIANT thanks to you. You totally answered every question I had.

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @dazmoe82 ya sorry about the music, there won't be any more music from now on.

  • @bigrig4966
    @bigrig4966 10 ปีที่แล้ว

    I literally love you for showing me how to do this, thanks man.

  • @jessiebrammer4768
    @jessiebrammer4768 10 ปีที่แล้ว +1

    This was really helpful! Thank you!

  • @RelearnMath
    @RelearnMath  13 ปีที่แล้ว

    @xBazingaProductionsx No it wouldn't work sorry, but you can just find the reference angles of higher degrees and use the "trick" for it. For example the sin(135) = sin(45) because 45 is the reference angle but in quadrant 2, since we know all sine in quadrant 2 are positive then the answer is the same

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว +1

    remember that negatives are reference angles so use that :)

  • @Raborat
    @Raborat 10 ปีที่แล้ว +1

    Woah i will use this forever thank you so much dude!

  • @chuksc-m.5579
    @chuksc-m.5579 12 ปีที่แล้ว

    This was very good, it helped me a lot. Keep them coming

  • @joshuadelafuent3
    @joshuadelafuent3 8 ปีที่แล้ว +1

    If only I found your channel when I was passing math lmfao, but it's good cause I'm going to use you're channel for all my retests now.

  • @KaiserFailed
    @KaiserFailed 9 ปีที่แล้ว +18

    I HAVE A TRIG AND ALGEBRA FINAL TOMORROW I SPENT SO MUCH MONEY FOR THIS CLASS I AM SOLID WITH THE ALGEBRA BUT A BIT UNSURE WHEN IT COMES TO THE TRIG STUFF THIS HERE IS CHANGING MY LIFE I LOVE YOU SO MUCH I WILL SCK YO' DCK FO' FREE.

    • @bacosack-7144
      @bacosack-7144 9 ปีที่แล้ว

      +KaiserFailed did you fail your exam tho

    • @KaiserFailed
      @KaiserFailed 9 ปีที่แล้ว

      +Bacosack - I sure as hell did NOT :D

    • @bacosack-7144
      @bacosack-7144 9 ปีที่แล้ว

      good job!! asked bc of ur username

    • @KaiserFailed
      @KaiserFailed 9 ปีที่แล้ว

      Bacosack - lmao KaiserWins! (finally)
      ;D

    • @Legendnos
      @Legendnos 8 ปีที่แล้ว

      KaiserFailed how was the exam 😂😂

  • @andrejamarsic3095
    @andrejamarsic3095 10 ปีที่แล้ว

    I was confused but now it all makes sense. Thanks so much!

  • @Visualizingmathandphysics
    @Visualizingmathandphysics 12 ปีที่แล้ว

    Sin is a measure of how much perpendicular two objects are.
    Hence sin(90)=1.
    Cos is a measure of how much parallel two objects are
    Hence cos(0)=1.
    Sin comes into picture when two things produce maximum effect working against each other.
    Cos comes into picture when two things produce maximum effect working parallel to each other.
    There are videos dedicated to trignometry on my channel if you. Actually also have a book written on such topics.
    Binnoy

  • @RelearnMath
    @RelearnMath  12 ปีที่แล้ว

    well -180 is the same as 0 degrees right?

  • @RelearnMath
    @RelearnMath  11 ปีที่แล้ว

    Nice keep it up man, you foundation will make things easier in the future if your good at geometry and algebra and really understand the concepts behind the math then more advanced classes will become easier, I learned this the hard way.

  • @rss_ruby
    @rss_ruby 9 ปีที่แล้ว

    This video was super helpful!! Thanks for making it!!

  • @iLOVEWHWT
    @iLOVEWHWT 12 ปีที่แล้ว

    I love you. U just saved my trig grade. This is a lot better than that stupid trig hand thing.

  • @jonathanpalcongvalente9670
    @jonathanpalcongvalente9670 9 ปีที่แล้ว +1

    hey bro, whats the band singing on your background? And I LIKE YOUR TUTORIAL! Helps me alot!

    • @RelearnMath
      @RelearnMath  9 ปีที่แล้ว

      Jonathan Valente I actually don't know, it was random music playing in the background sorry.

    • @alexmercer8925
      @alexmercer8925 9 ปีที่แล้ว

      +Jonathan Valente The song at 4:53 is Sick Puppies-You`re going down ;)

    • @dayswillburn777
      @dayswillburn777 8 ปีที่แล้ว

      Right side of the bed by Atreyu

    • @dayswillburn777
      @dayswillburn777 8 ปีที่แล้ว

      +I, Killastrata first song at least

  • @dulcyb9716
    @dulcyb9716 7 ปีที่แล้ว

    WHAT ARE YOUR CALCULATOR SETTINGS!!???? I keep getting decimals and im not sure how to fix it.

  • @xBazingaProductionsx
    @xBazingaProductionsx 13 ปีที่แล้ว

    hey, would it still work if we continued using angle measures from the unit circle? For example, instead of just going from 0 to 4, we could go to like, 0 to 10, with the correct corresponding angle measures from the unit circle of course. let me know, thanks :)

  • @saxxobeat
    @saxxobeat 12 ปีที่แล้ว

    thank you sooo much!!!! i have to take a test tomorrow and this trick is incredibly helpful!!!

  • @scene2all
    @scene2all 11 ปีที่แล้ว

    when you type in a trig value on you calculator, you get it in surd form. Does this work on Casio calculators as well?

  • @Beastninja33
    @Beastninja33 11 ปีที่แล้ว

    So, what about csc,sec, and cot? Would you just switch the 2 and the square rooted number from what you found?

  • @startiger411
    @startiger411 10 ปีที่แล้ว

    Oh my gosh. This is so helpful. Thank you for posting this!!!!

  • @AG-ty4no
    @AG-ty4no 12 ปีที่แล้ว

    I'm having trouble with identities, half angles, double angles and of course inverse functions. If you have any tips or tricks that will help I'd appreciate it. Thank you Iris

  • @myb278
    @myb278 2 ปีที่แล้ว

    Thanks so much, this is the most helpful table, my teacher just said to memorise them but this table is so much better

  • @acidman10
    @acidman10 9 ปีที่แล้ว +1

    thanks very much for posting. you are awesome. i had heard of this trick, but forgot how to use.

  • @anthonyfuentes512
    @anthonyfuentes512 12 ปีที่แล้ว

    What song are you listening to in the background?

  • @SamFootballnG
    @SamFootballnG 10 ปีที่แล้ว +5

    What happens when you have an angle bigger than 90?!?!?!?

  • @leoboivin3224
    @leoboivin3224 9 ปีที่แล้ว

    I am trying to compute pi and unfortunately, i can't compute the sine of numbers like 9*10^(-8). Could you teach another trick for numbers less than 1? If possible, of course. ;) Nice video, by the way!

  • @zeinaalhalabi4557
    @zeinaalhalabi4557 10 ปีที่แล้ว +3

    Dude you're a legend.

  • @FamiliaSimoneGuille
    @FamiliaSimoneGuille 12 ปีที่แล้ว

    Thanks, it's been really helpful. Now, how do I do with negatives angles? Do I just change the sign?
    Thanks.

  • @nguyenphithoaihung
    @nguyenphithoaihung 7 ปีที่แล้ว

    Thank you so much for this trick. I wish professor's would learn tricks like this.
    If you can keep the paper in one place, it would greatly help the future viewer. Thanks again.

  • @clw766
    @clw766 13 ปีที่แล้ว

    SO HELPFUL!!!! I'm about to take a test in a few minutes im going to ace it now!

  • @unaccompaniedvlogger582
    @unaccompaniedvlogger582 10 ปีที่แล้ว

    i have a quarter exam tomorrow, this helped a lot :)!

  • @fergusthewestie
    @fergusthewestie 11 ปีที่แล้ว

    Really liked this video but what do you do if you are asked to find exact values for say, tan 75 or sin 100?

  • @midnightmoon9511
    @midnightmoon9511 5 ปีที่แล้ว

    Ah how time flies now we have hand tricks. I never experienced this method but I'm still missing it for some reason lol

  • @Rodneyconan
    @Rodneyconan 11 ปีที่แล้ว

    Could you post a vid on how to use coterminals to find the exact values?

  • @masudranatunu
    @masudranatunu 11 ปีที่แล้ว

    in a word , this is just awesome :)
    thanks mate

  • @xJAZZxITxUPx
    @xJAZZxITxUPx 12 ปีที่แล้ว

    you should do a video on double angle and half angle indentities

  • @linmp2709
    @linmp2709 8 ปีที่แล้ว +1

    How do find the exact value of sin75 degrees WITHOUT using and processing any high level trigo identity (e.g. sin(A+B) ) and calculator?

    • @linmp2709
      @linmp2709 8 ปีที่แล้ว

      How
      Do you find

    • @tolbryntheix4135
      @tolbryntheix4135 8 ปีที่แล้ว

      I was breaking my head trying to find out how to calculate these with an equation (using the ratio of the spuared sinus and cosinus) but I always ended up only finding the equations leading to rounded graphs which you can't perfectly describe with an equation (calculus leaves parts out so it isn't describing it exactly). I asked my teacher and he said that without calculator they just use lists with the side ratio-degree and the calculator uses software to measure the side length and degree. Hope that anwsered your question.

    • @linmp2709
      @linmp2709 8 ปีที่แล้ว

      Well, there is a expression for sin 75 degree in terms of square root, which you can find by drawing a geometric figure

    • @tolbryntheix4135
      @tolbryntheix4135 8 ปีที่แล้ว

      Will Wong but if you have some random degree, there isn't any equation you can just put that degree in to find sin or cos. (Tan is do-able)

    • @RelearnMath
      @RelearnMath  8 ปีที่แล้ว

      The only way to get an exact value(really its just a really close approximation) of Sin/Cos/Tan by plugging into an equations is by using infinite series. You can google, Sine Taylor Series and you should be able to find it, theoretically, if you use an infinite number of terms you will get the exact value, however if you simply want a really good approximation you only need to use a few of the terms. I have a video where I use 3 or 4 terms(i forget) and it is enough to give me the calculator value. So for all intents and purposes it's good enough.

  • @Soccer4life961
    @Soccer4life961 11 ปีที่แล้ว

    HI, how do i find cos 270? would it not be cos = 0 so there for using this table it should be 1? kinda confused

  • @MrJoshDada
    @MrJoshDada 11 ปีที่แล้ว

    whats the song in the backround? it sounds extremely familiar, like breaking benjamin.

    • @livefastplaydirty
      @livefastplaydirty 10 ปีที่แล้ว +3

      its atreyu

    • @wpp6986
      @wpp6986 10 ปีที่แล้ว +2

      "You're going down" - Sick Puppies

  • @eyediaz6834
    @eyediaz6834 4 ปีที่แล้ว +1

    Nice music in the background. I love metal music.

  • @XXdragoneyeX
    @XXdragoneyeX 11 ปีที่แล้ว

    How do you get your calculator to give you exact answers?

  • @RailTsuiSliver
    @RailTsuiSliver 12 ปีที่แล้ว

    What if you only have graphing calculator ? And what is the angles are 150?225?

  • @sleepyspades5386
    @sleepyspades5386 9 ปีที่แล้ว

    Thank you sir! I have an algebra test real soon and this really helped!

  • @seanmueller6445
    @seanmueller6445 11 ปีที่แล้ว

    How do find the negative of an angle? Lets say -cos(0)? Or -sin(60)?

  • @thesecondantagoniser4008
    @thesecondantagoniser4008 8 ปีที่แล้ว

    so therefore, If I was evaluating 65 degrees multiplied by sine I would get 3 1/6, since there are six 5's from 60 to 90 and 60sine is equal to 3 and 90sine is equal to 4.
    I'm stuck on evaluating Tan65 degrees so I could use some help. Cheers!

  • @ahmadiqus
    @ahmadiqus 10 ปีที่แล้ว

    whats with song in the background?

  • @dannylauu
    @dannylauu 11 ปีที่แล้ว

    also how would i find like tan1 or something like tanroot3 using this graph

  • @darl2588
    @darl2588 10 ปีที่แล้ว +3

    Thank you so much! Why don't public schools teach this? I am finally learning this as a college student. Wow.

    • @RelearnMath
      @RelearnMath  10 ปีที่แล้ว +1

      I actually learned this my first semester of college haha.

  • @RelearnMath
    @RelearnMath  11 ปีที่แล้ว

    anything co-terminal with the given degrees.

  • @AG-ty4no
    @AG-ty4no 12 ปีที่แล้ว

    Thank you soooo much for the trig trick, do you have any new stuff that relates to identities and such? Its getting trickier for me and I need the help. THANKS!!!!

  • @brenna1163
    @brenna1163 10 ปีที่แล้ว

    This is awesome! One issue though... What if you have an angle greater than 90 degrees? Can you still use that basic set up but use the coterminal angle? For example, a question on my assignment says: "Find the exact value of sin(1290*)" How would I go about that using this method? I would love a video over that!! Thank you :)

    • @RelearnMath
      @RelearnMath  10 ปีที่แล้ว

      yes, conterminal angles work since values just repeat.