The exact values for sin and cos 0, 30, 45, 60 and 90

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  • Опубликовано: 21 дек 2024

Комментарии • 19

  • @na-mn9bx
    @na-mn9bx 6 лет назад +6

    Thanks hopefully this will help me get a decent grade on my test

  • @rifaiqbal1131
    @rifaiqbal1131 8 лет назад +7

    Can u please do a video on sin cos and tan graphs and the transformations of them.

    • @mathsgenie7808
      @mathsgenie7808  8 лет назад

      Rifa Iqbal yeah I will try to get that done

  • @charlottem2086
    @charlottem2086 7 лет назад +15

    Why didn't you explain cos90 or sin90? I can't find anywhere on the internet that explains how sin 90 is 1 and I'm so confused

    • @user-bv6gs4qw9k
      @user-bv6gs4qw9k 6 лет назад

      he showed sin90 is 1 by using the graphs at the beginning

    • @user-kw8go6ok5g
      @user-kw8go6ok5g 6 лет назад +2

      @@user-bv6gs4qw9k i would have loved to see the diagram, especially for cos 90... but sure

    • @enkvadrat_
      @enkvadrat_ 9 месяцев назад

      @@user-kw8go6ok5gtake a look at the unit circle (i know this is 5 years ago, but someone else may wonder the same thing)

  • @rebeccajohn8672
    @rebeccajohn8672 5 лет назад +4

    I knew sin(45) was 1/root 2, but on all the other videos and pictures that i've seen, it says that its root 2/ 2.
    Why is this? Which value is the correct one?

    • @zazai3883
      @zazai3883 5 лет назад +5

      Rebecca John that is the rationalised version of 1/root2

    • @bensmith9128
      @bensmith9128 4 года назад +2

      They are the same value. Check on a calculator if you want. A fraction is equal if we multiply the top and bottom by the same number. If we multiply 1/root 2 by root 2 on the numerator and denominator we end up with root 2/2 hence they are the same.

    • @ollie5845
      @ollie5845 2 года назад +1

      √2/2 is the rationalised surd - better to remember. The values for sin go 0, 1/2 (which is √1/2), √2/2, then √3/2, then 1 (which is √4/2) - see the pattern?

  • @tinotv7766
    @tinotv7766 7 лет назад +10

    i hate when you magically work things out without saying how you got there... from 3:23 to 3:35???????????????

    • @Sai-rp2xt
      @Sai-rp2xt 7 лет назад +6

      Pythagoras theorem says
      a^2 + b^2 = h^2
      where h is the longest side (side opposite to right angle) and a and b are the other two sides of a right angle triangle.
      Let a = x, b = 1, and h = 2.
      So you get x^2 + 1^2 = 2^2.
      1^2 = 1 and 2^2 = 4.
      So you get x^2 + 1 = 4.
      - 1 from both sides of the equation.
      This is because there is a "+ 1" next to the x^2 and we're trying to get x on it's own so we do the inverse of + 1 which is - 1.
      So you get x^2 = 3.
      Square root both sides of the equation.
      This is because x^2 means the x is squared and we're trying to get x on it's own so we do the inverse of squaring which is square rooting.
      So you get x = √3.
      I hope this helps. I'm not very good with words. Even if it's too late to help you, I hope it helps someone.

    • @bearamon9918
      @bearamon9918 5 лет назад +3

      Thats pythagoras... does he have to explain it? If you’re watching a video on exact trig values you should’ve been taught pythagoras by now

  • @VijayaKumar-re9fh
    @VijayaKumar-re9fh 4 года назад +3

    OMG ..😱 .. I'm freakin' for the way u spoke English... I'm gonna die ... Actually I'm not good in English.... So.. I haven't understand what u spoke 😅...

  • @christan8844
    @christan8844 7 лет назад +1

    Charlotte...cos of 90 = 0 and sin of 90 = 1...remember the Beatles...1,2,3,4 can I have...

  • @walidabusaa1763
    @walidabusaa1763 7 лет назад +2

    thanks for that

  • @settledownbeavis6537
    @settledownbeavis6537 2 года назад

    What u dont lead for children without gradt we do xxx

  • @loveofaflower5486
    @loveofaflower5486 3 года назад

    THANKSSSSSSSSSSSSSSSSSS