Rational Numbers | Definition + First Proof

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  • Опубликовано: 30 янв 2025

Комментарии • 32

  • @Salvation1984
    @Salvation1984 4 года назад +12

    I looked at my class slides and got so frustrated cause I had no clue what it meant, watched your video, now everything is clear! Thank You!!

    • @DrTrefor
      @DrTrefor  4 года назад +1

      Glad it helped!

  • @hpp6116
    @hpp6116 6 лет назад +21

    You are an excellent teacher!

  • @MrConverse
    @MrConverse 2 года назад +4

    4:21, (and a few additional times), you said that you’d get the lowest common denominator. You did get a common denominator, and that’s all you needed, but it is not necessarily the lowest.

  • @andrewscott2791
    @andrewscott2791 9 месяцев назад

    I go to ucla, paid something around 1k for this class to be confused, your video might be the thing that saves me.

  • @devdin8157
    @devdin8157 4 года назад

    Almost halfway through the discrete math course, Thank you very much for these videos.

  • @lemushkairitu6492
    @lemushkairitu6492 4 года назад +2

    Thank you so much,your lectures saved me👏👏👌

  • @tyziesyke5073
    @tyziesyke5073 2 года назад

    You have saved a soul

  • @s_t_a_r__xyz9954
    @s_t_a_r__xyz9954 3 года назад +2

    Well done sir

  • @sangurajeswari7191
    @sangurajeswari7191 3 года назад +1

    Tq you sir you solved my problem

  • @webknowledge9989
    @webknowledge9989 2 года назад +1

    I watch these videos and then go to the book "Introduction to Algorithms" or CLRS and see how much more I understand.

  • @avinashbajpai325
    @avinashbajpai325 4 года назад

    Wow amazing to listen from you

  • @vayramjosh
    @vayramjosh 3 месяца назад

    or 22/7.... assuming I am trying to proof rationality of 22/7, what strictions can i include in my proof.

  • @vayramjosh
    @vayramjosh 3 месяца назад

    is 2/1 a rational number ?

  • @likethewordsmith
    @likethewordsmith 3 года назад

    Why we represent rational number as p/q (where p and q are integer and q not equal to zero).proof ?

    • @RajdeepMehta
      @RajdeepMehta 3 года назад +1

      Good to know that Indian are also watching 😂 👍🏻👌🏻

    • @zzzzzzzjsjyue2175
      @zzzzzzzjsjyue2175 2 года назад

      There is no proof. That’s the definition

  • @stargazer8718
    @stargazer8718 2 года назад +1

    Despite having watched this many times, I still don't understand. Since it can't be more clear than this, how can I ever understand? Seems that my college degree is doomed to fail.

    • @andescosmico3016
      @andescosmico3016 2 года назад +1

      Yes, it can be more clear if it would say:
      m+n=(p1.q2+p2.q1)/(q1. q2),
      but
      (a) the numerator (p1.q2+p2.q1) is an integer, let us call it p3, and
      (b) the denominator q1.q2 is also an integer let's call it q3,
      from (a) and (b) we get that m+n= p3/q3 where p3 and q3 are both integers,
      hence m+n is rational
      This proof is less formal than the one on the video, but it may be more clear.

    • @emilyau8023
      @emilyau8023 2 года назад

      @@andescosmico3016 your explanation was more clear. Thank you.

  • @joaobrites5931
    @joaobrites5931 4 года назад

    What if you wanted to prove the other way around? Given that the sum of 2 numbers is rational, prove that they are both rationals.?

    • @DrTrefor
      @DrTrefor  4 года назад +1

      That statement (the converse) isn't actually true. pi + -pi=0 which is rational

    • @joaobrites5931
      @joaobrites5931 4 года назад

      @@DrTrefor yes yes. i forgot a important part sorry. the question goes like this :if the sqrt(a) + sqrt(b) is rational, prove that sqrt(a) and sqrt(B) are rational. thank you.

  • @cringy7-year-old5
    @cringy7-year-old5 Год назад

    pretty cool

  • @ytseberle
    @ytseberle 3 года назад

    Nice video. But you keep saying q1q2 is the lcd of q1 and q2.

  • @jackcastro7259
    @jackcastro7259 4 года назад

    very well explained . wishing to be smart as you hahahha

  • @utopiad4
    @utopiad4 3 года назад

    Is 0.23 rational or irrational

  • @stuartkent383
    @stuartkent383 2 года назад

    My kids year 8 homework asked if the √20 is rational. If I was smart enough to understand this, then I might know. Oh well!

  • @fatmafaizal07
    @fatmafaizal07 5 лет назад

    wow