Solving the logistic differential equation part 1 | Khan Academy

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  • Опубликовано: 5 ноя 2024

Комментарии • 39

  • @zhaoyangxie4396
    @zhaoyangxie4396 4 года назад +9

    Great video. Just have one question: why don't you use separation way just like what you did in the previous videos? Thanks.

    • @Syndicalism
      @Syndicalism 2 года назад +2

      I know this is a year late reply but he does use separation of variables. First thing he does. He then does partial fraction decomposition to help find the anti derivative on the LHS of the equation.

  • @rebeccadoorley83
    @rebeccadoorley83 8 лет назад +13

    was completely with you until 7.20m havent a clue after that!

    • @marioleon4128
      @marioleon4128 5 лет назад +5

      pretty much he linearized the whole integral that was created by using partial fractions and broke that big integral up into two smaller ones like this: 1/n + (1/k)/(1-n/k)dn/dt = r
      Is the same as ↳ ∫1/n +(1/k)/(1-n/k)dn = ∫r dt

    • @randomeggthatworksforthefb7172
      @randomeggthatworksforthefb7172 3 года назад +1

      @@marioleon4128 I did help! even though this is two years later haha

  • @13identity
    @13identity 9 лет назад +18

    Holy cow this is loooong and complicated.

  • @meltemkaya9725
    @meltemkaya9725 4 года назад +4

    if we regulate 1/(1-N/K) as K/(K-N) then we can see K/N(K-N) = 1/N - (-1)/(K-N). And the solution will be easier.

    • @dibehemoth401
      @dibehemoth401 3 года назад

      Yeah. The problem can be solved way faster this way.

    • @ipeklacin2918
      @ipeklacin2918 Год назад

      helal meltem as bayrakları

  • @athenovae
    @athenovae Месяц назад

    11:21 I think you’re missing 1/k in front of the second ln.

  • @BiscuitZombies
    @BiscuitZombies 4 года назад +3

    11:15 The integral of (-1/k)/(1-n/k) with respect to n is 1/k * Ln(1-n/k), note the 1/k coefficient. Why does yours not have a coefficient?

    • @zareefamyeen6925
      @zareefamyeen6925 4 года назад +1

      The integral of (-1/k)/(1-n/k) IS -ln(1-n/k). If you use u = 1-n/k you should get integral of - du/u = - lnu

    • @athenovae
      @athenovae Месяц назад

      I was just about to say. He’s missing it.

    • @BiscuitZombies
      @BiscuitZombies Месяц назад

      @@athenovae I have since realised that what I said is wrong. the 1/(1-n/k) produces a factor of k at the front. This cancels the -1/k.

  • @hrushikeshmandekar6572
    @hrushikeshmandekar6572 3 года назад +1

    Thanks, it helps me lot.

  • @YouUndeground
    @YouUndeground 5 лет назад +1

    Thank you!

  • @peter_roth_8812
    @peter_roth_8812 10 лет назад +2

    Geat job how you did this partial fractions expansion.

    • @stevenson720
      @stevenson720 7 лет назад

      Hans Peter Roth
      yep. I had completely forgotten that was a thing

  • @prosimion
    @prosimion Год назад

    thank you once again sir....sorry I haven't said that in a while.

  • @rogelioherbolingo2843
    @rogelioherbolingo2843 2 года назад

    Is separable equation with an implicit or explicit solution not applicable in this situation??

  • @nullheim
    @nullheim 9 лет назад +4

    Well at 6:33, I didnt use the partial fraction like you, I used 1/(K-N) instead of using (1/K)/(1-(N/K)). Here is the problem ; mathematically they are exatly the same, but I got different answer, my calculations are right just like yours. Aren't they same expressions, if not, can you tell me why not? I found the equation as follows :
    N(t)=((KN.)/(e^(-rt)K+N.)) yours is N(t)=((KN.)/((K-N.)e^(-rt)+N.)) only different thing between our functions is you have coefficent (K-N.) to e^(-rt), mine has a coefficient K

    • @prabinlamsal5125
      @prabinlamsal5125 4 года назад +1

      Facing the same problem after more than 4 years man.

  • @dialaali9510
    @dialaali9510 3 года назад

    can you help me with (computing the poincare map )?
    and thank you for this video its helpful

  • @mohbada1134
    @mohbada1134 4 года назад

    What is demographic explanation of K

  • @lyfxyz12
    @lyfxyz12 9 лет назад +2

    goooood video

  • @dragonbrave8
    @dragonbrave8 10 лет назад

    mathematics is so versatile, is like water taking the shape of its vessel.
    Im stuck at 8:44, I don't get that Ln derivative.

  • @ConnorMooneyhan1
    @ConnorMooneyhan1 7 лет назад +4

    At 7:30, I'm very confused. Why are we taking the antiderivative with respect to N and then taking the antiderivative of that with respect to t?

    • @NazmusLabs
      @NazmusLabs 7 лет назад

      Connor Mooneyhan he wasn't. He was just showing you that you CAN take antiderivatevs with respect to t as well because T is a dependent variable of N. He showed you both options.

  • @Clin270
    @Clin270 4 года назад +1

    1337, nice

  • @tauseefahmedmemon9148
    @tauseefahmedmemon9148 6 лет назад

    how is he taking derivative of terms with no "t" in them w.r.t "t" and not making them 0???

  • @gexwing
    @gexwing 10 лет назад

    haha part 1 isn't showing in my inbox, yet here it is :)

  • @StainlessSteelFaucet
    @StainlessSteelFaucet 4 года назад

    I'm in pain

  • @Wondermass
    @Wondermass 7 лет назад

    We did a video (featuring the logistic equation) about where equations come from in social science: ruclips.net/video/zXY6LEwHgaI/видео.html

  • @ShiroWretchedEggX
    @ShiroWretchedEggX 9 лет назад

    Much easier to solve if you know how to solve bernoulli equations.

  • @bobabooks
    @bobabooks 2 месяца назад

    nft haha

  • @grozkid
    @grozkid 7 лет назад +9

    terrible

  • @Catadventures131
    @Catadventures131 6 лет назад +2

    Calculus sucks