Understanding the number e | BetterExplained

00:09:15
https://www.youtube.com/watch?v=yTfHn9Aj7UM

Résumé

TLDRVideoen præsenterer essensen af den matematiske konstant e, som er central for at beskrive kontinuerlig eksponentiel vækst. Gennem enkle eksempler forklares det, hvordan e er relevant i både naturlige processer og finansiel vækst. Indlægget fremhæver, at e repræsenterer 100% vækst og er unik ved at være en jævn, glat vækstform uden pludselige spring, som ofte ses i naturlige processer - for eksempel cellevækst - og økonomiske mekanismer som renter, hvor både hoved- og renteværdier kan tiltrækkes af yderligere renter. Formlen e^rt (e til kraften af rente gange tid) forklarer fleksibiliteten i at ændre vækstrater over tid. Denne konstante natur gør e til en uundgåelig del af mange matematiske formler givet dens universalitet i vækstbeskrivelse.

A retenir

  • 📈 e er en universel konstant for eksponentiel vækst.
  • 🧬 Naturlige processer, som cellevækst, følger ofte en kontinuerlig vækstkurve.
  • 💸 I økonomi tillader e beskrivelse af renter, der vokser kontinuerligt.
  • 🔄 Kontinuerlig vækst betyder jævn, ikke-springende vækst.
  • 🧮 e bruges i formler takket være dens konsistens i at beskrive vækst.
  • 🎯 100% vækst kan teknisk beregnes som en fordoblingsrate.
  • 🔍 e kan justeres ved hjælp af forskellige vækstrater i formler.
  • 🌿 Vækst i naturen og økonomi deler lignende grundprincipper takket være e.
  • 📊 Vækst ved e er en uendelig række af små incrementer.
  • 🧾 Forståelse af e hjælper med at forstå logaritmiske mønstre i vækst.

Chronologie

  • 00:00:00 - 00:09:15

    Khalid fortsætter med at beskrive, hvorfor e er universel og fleksibel. E udtrykker 100% kontinuerlig vækst og kan skrives som e^rt, hvor r er raten og t er tiden. Selvom r ofte er 100%, kan den tilpasses til fx 50%, hvilket ændrer vækstkurven passende. E kan også tilpasses for at matche hakket vækst, som 2^x, ved at sammenligne det med en glat kurve e^q. Han konkluderer, at e ikke er magisk, men simplificerer vækstforståelse ved færrest mulige antagelser om kontinuerlig, jævn vækst uden ujævnheder.

Carte mentale

Vidéo Q&R

  • Hvad er e?

    E er en matematisk konstant, der repræsenterer det naturlige basis for eksponentiel vækst. Det er cirka 2,718.

  • Hvordan relaterer e til vækst?

    E repræsenterer kontinuerlig vækst, hvilket betyder, at den beskriver en proces, hvor mængden konstant vokser på en glat og ikke-jagged måde.

  • Hvorfor er e universel i formelbrug?

    E anvendes universelt i formler, fordi den pålideligt beskriver kontinuerlig vækst, et fælles fænomen i både naturlige og finansielle processer.

  • Hvordan anvendes e i finansiel vækst?

    I finansiel vækst beskriver e, hvordan penge vokser via renter, hvor også renterne selv kan forrente sig, hvilket repræsenterer en uendelig række af små væksttrin.

  • Hvad betyder 100% vækst i konteksten af e?

    100% vækst refererer til, at den oprindelige mængde fordobles efter en given periode, hvor væksten sker kontinuerligt over tid.

  • Hvordan kan e modelleres i andre vækstformer?

    E kan modellere forskellige vækstformer ved at justere vækstraten over tid, hvilket tillader variabilitet fra fx 50% til 100% vækst.

  • Hvad er betydningen af kontinuerlig vækst?

    Kontinuerlig vækst betyder, at væksten sker jævnt og uden pludselige spring i værdien, modsat en trappelignende vækstform.

  • Hvordan kan e anvendes i naturprocesser?

    I naturprocesser kan e illustrere glat vækst over tid, som hvordan celler deler sig og vokser gradvist.

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Sous-titres
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Défilement automatique:
  • 00:00:00
    hey guys this is Khalid here I just want
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    to give you a quick overview about the
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    key insights about e this is essentially
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    what I wish it could have gone back in
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    time and told myself about e you know
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    way back in high school already here we
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    go okay e is essentially epitome of
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    universal growth what does that mean why
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    is it universal well we can start off
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    with regular growth if you consider
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    something that changes over time like a
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    simple progression is doubling right so
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    you are a time one you have certain
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    amount of time to you double a time
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    three you double again so you have four
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    and so on and you basically have some
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    kind of exponential curve and then we
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    can call this two to the X so that's so
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    amount of time you know as you go along
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    you basically get some amount of growth
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    happening now this might seem Universal
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    and it is for a few reasons the first is
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    that - that's 100% growth which
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    basically means that you're doubling by
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    the amount that you have so it's kind of
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    universal that sense right it's a unit
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    growth so if you want if you triple
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    that's kind of you know 200 percent
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    growth which is you know it's not
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    exactly is clean as 100 percent growth
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    so there is a cool kind of you know
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    symmetry here where you're growing by
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    the amount that you have so basically
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    this goes here and then you get a new
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    interest and then these go here and you
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    get new interest as well so 100 percent
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    is kind of a neat idea but there's a
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    problem you waited until the end of the
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    period to get all your interest
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    you had nothing you were just normal
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    then suddenly boom this guy popped in
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    out of nowhere and this actually isn't
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    that common right if you think about
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    natural processes things don't just
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    appear out of nowhere they grow slowly
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    over time for example take a look at a
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    cell if we start with same idea of
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    growth we might have a cell and over
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    time it has a little buddy and this
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    little buddy
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    is kind of emerging out of them right
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    and eventually it'll pop out so it
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    didn't pop out all of a sudden over time
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    it's sort of emerged and then each day
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    got a little bit more and finally it was
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    a new soul of its own so the idea is
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    that instead of getting all your growth
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    at the end which happens with
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    to to the X that we saw kind of like a
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    staircase right it sort of goes up like
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    that we're talking about kind of as more
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    smooth gradual growth so if you think
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    about this this is actually the more
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    like nature right in nature things grow
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    slowly over time they don't sort of
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    suddenly appear out of nowhere and have
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    a kind of a discontinuous jump so if you
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    really want to have a universal way to
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    talk about growth it really should be
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    more of a smooth change instead of kind
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    of a staircase like pattern because
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    really that never happens things you
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    know don't happen isn't aeneas lee it
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    happens over time now there is one
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    little side effect though when we're
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    growing this cell it couldn't actually
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    grow on its own we sort of waited until
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    we had a red cell and then that red cell
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    could start having its own interest like
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    a green cell coming out so we have a red
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    cell and then we have a green cell
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    emergent right so the red was kind of
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    stuck in the green started coming out as
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    well so this again isn't quite as smooth
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    as it could be because while we're
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    growing the red the red can't grow on
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    its own and one kind of neat thing is
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    that money actually it's a good example
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    of something which doesn't have this
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    problem so here's the idea if you're
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    looking at the way money grows we might
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    have one dollar and over time it's a
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    dollar but you know what it earns
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    interest so as time goes on your dollar
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    earns interest and eventually you have
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    the new dollar shiny new dollar all for
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    yourself but the cool thing is that with
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    money interest can earn interest so this
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    red amount that you earned well that can
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    own own its own interest here which kind
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    of shows up here and this green interest
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    well it can earn its own may Brown
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    interest that shows up here as well if
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    you look at the article there's kind of
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    a worked example but the idea is this
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    your regular amount come goes along like
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    that it earns some interest which is
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    this kind of red growth here and that
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    red growth well that earns its own
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    interest which is this kind of green
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    growth here and that green growth earns
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    its own interest which is this brown
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    growth and so on so there's actually an
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    infinite amount of growth happening and
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    it sort of looks like that so what ends
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    up happening is you get this curve which
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    has sort of an infinite number of
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    opponents the biggest components come
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    from these kind of giant chunks in the
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    beginning but you end up having smaller
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    and smaller groups emerging so it's a
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    bunch of little slices and eventually it
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    caps out here's the idea
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    E is that cap so if you add up all the
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    slices you get growth which is actually
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    e to the X so E is basically the idea of
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    taking growth adding its and Trust
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    adding bats interest adding bats
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    interest and so on and so on and each
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    time you do it it gets a little bit
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    narrower and narrower and the max speed
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    limits you hit that's e so the reason is
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    Universal is the following one it's 100%
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    growth so the idea is that your original
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    item it'll actually double itself at the
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    end of one period so you start at you
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    know let's call this time zero at the
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    end of one period your black amount has
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    actually doubled itself so that's why
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    it's how 2 percent growth but two it's
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    continuous and this is really the key
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    here it's not jumping suddenly as time
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    goes on each instant is earning red and
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    the eds
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    the Reds earning green and the Greens
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    earning brown and the Browns earning
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    gray and so on and so on so this
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    combination actually that gives you some
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    amount of growth at the end of the
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    period which is about 2.718 dot and that
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    number is and basically if you want to
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    find out how much growth you have at the
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    end of two periods or three periods you
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    just take e to some exponent so the
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    reason that he appears in every kind of
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    formula is because it's a very common
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    base to verse Allah to talk about growth
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    and you can actually change the rate so
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    this is actually okay now jumping into
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    the kind of flexibility B so E is
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    basically 100% continuous growth but
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    it's also flexible so E I actually
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    consider it e to the RT so this is e to
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    the rate times time
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    often times the rate is 100% so you
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    don't see it because 100 percent is 1.0
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    right so you don't actually see it it's
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    you know invisible but the idea is that
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    if you adjust the amount of interest
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    that you get at the end of a period so
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    right
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    100% let's say you only get 50% interest
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    so you'd have something like this you're
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    growing and at the end of one period
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    you only get 50% not 100% interest you
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    still have the same thing that interest
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    you know earn some of it yourselves own
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    50% and you get 50% of that let's see we
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    had brown coming up ended 2% of that
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    grey coming up so you still get a
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    pattern but it's a little bit reduced
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    and the idea is oh in this case it would
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    actually be e to the point 5 because
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    it's 50% interest and then times the
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    amount of time that you want to you take
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    it for so you could have 50% interest
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    for 2 years and it actually would be the
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    same thing as 100 percent interest for 1
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    year because 50% times 2 equals 100
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    percent times 1 so the cool thing about
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    these is really flexible you can adjust
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    the rate in time and that works because
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    it's based on very universal principles
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    100 percent growth and it's continuous
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    so there's no kind of jagged edges so
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    that's sort of the key insight about e
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    the article has some kind of
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    computations but here's one little cool
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    fact you can actually model the
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    staircase like growth so if we have this
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    kind of jumpy growth right that's sort
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    of appearing out of nowhere e can
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    actually match that to some smooth curve
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    so that will be e to some interest rate
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    I don't know let's call it Q or
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    something right so e to the Q that can
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    actually match up with any kind of
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    jagged interest rate that you want into
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    the hood it'll hit all the points so the
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    neat thing is that any kind of growth
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    can be considered on its own is this
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    jagged growth or it can be considered as
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    e raised to some interest rate and the
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    idea here is that you can actually use
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    the natural logarithm to figure out what
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    interest rate that is but we'll get to
  • 00:08:28
    that separately so again the ideas
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    behind e 100% growth is growing by
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    itself you start with something it grows
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    and it earns interest it is itself which
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    earn some interest on its own and so on
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    and so on and also it's continuous it's
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    smooth it's not jagged like this it's a
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    smooth curve and because of that you can
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    vary this growth from 100 percent to 50
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    percent growth which actually changes
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    the curve to be
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    lower and depending on how much you
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    angle it you can actually model any type
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    of growth that you want so that's my aha
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    moment about it's not this magic number
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    it's not a magic spell it's just taking
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    the idea of growth and simplifying it to
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    have this few assumptions as you can be
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    growing by yourself a hundred percent
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    and don't be jagged and with that you
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    get happy mess
Tags
  • e
  • eksponentiel vækst
  • kontinuerlig vækst
  • naturlige processer
  • finansiel vækst
  • 100% vækst
  • renter
  • matematik
  • formler