Limit of 2^n/n! as n goes to infinity

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  • เผยแพร่เมื่อ 1 ก.พ. 2025

ความคิดเห็น • 9

  • @reizinhodojogo3956
    @reizinhodojogo3956 2 หลายเดือนก่อน +1

    i just through about 2^n being 2×2×2×... } n times and n! being (n)(n-1)(n-2)(n-3)..(2)(1), where n! grows the multipliers faster than 2^n, so it tends to 0 as the divider gets bigger

  • @GeoPeron
    @GeoPeron 3 หลายเดือนก่อน +5

    The way I did it (probably not very correct but still):
    Σ[n=0,∞] 2^n/n! = e² (by the Maclaurin series for e^x), or in other words, the series converges.
    With that, the limit of the inside function must be 0 for it to bypass the test for divergence.

    • @OneLemmaAtATime
      @OneLemmaAtATime  3 หลายเดือนก่อน +2

      Very nice!

    • @aouerfelli
      @aouerfelli 14 วันที่ผ่านมา +1

      You just provided a way to prove that an exponential with any base is negligible against the factorial. In other words, we can replace the 3 with any other number, and the limit is still 0.
      Nice!

  • @divEdanslevide
    @divEdanslevide 3 หลายเดือนก่อน +2

    Stirling

  • @Entification
    @Entification 3 หลายเดือนก่อน +8

    2^n / n!
    At n=1, we get 2/1
    At n=2, we get 4/2
    At n=3, we get 8/6
    At n=4, we get 16/24
    At n=5, we get 32/120
    At n=6, we get 64/720
    At n=7, we get 128/5040
    We can make the observation that it's clear that the higher 'N' gets, the smaller this ratio becomes.
    Hence, it is getting closer to 0 as 'N' gets higher, so
    Lim 2^n/n! = 0
    n => INF

    • @robertveith6383
      @robertveith6383 2 หลายเดือนก่อน

      That's false reasoning. What you saw is that the value of the fractions are decreasing. You do not know that they are approaching zero from your list.

  • @fullestegg
    @fullestegg 3 หลายเดือนก่อน +3

    0