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Anti-APTX4869

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Posts posted by Anti-APTX4869

  5. Posted · Report reply

    Hi folks! Back to:

    A. Give answers to Sammie19 (no one's answering her!)

    B. Post a question here

    C. Do other stuff

    And now, here is the question for the Math Thread!

    1/1x2x3 + 1/2x3x4 + 1/3x4x5 + ... 1/98x99x100.

    Normal calculators can't help you here. There is a need for a certain formula that enables cancellation, but that can be discovered :)

    @Rye- hey how was Nationals? Probably saw you there. Everyone who won first was from NCR-B! And almost everyone that one was a boy! I think the 3rd placer from Grade 6 Individuals with a weird name and one of the team members of the team that won 2nd place in Grade 6 with a long name were the only girls...That has me thinking on why Math is a "boy subject"....

    A. ? Where? I'm assuming some names changed or something...

    B. Is there a level restriction?

    C. Other stuff... Well...

    Challenge accepted.

    First of all.... Just for laughs.

    I don't know why, but I feel stupid for making this even more complicated by thinking this first...

    5507e8b28d944ab79538ea77f791187b.png

    ..... which does give same result but....

    ...let's make it simple...

    I'm pretty confident about my answer, but I can't say for sure about any typos I made....

    Took me a while to type them up in Microsoft Word...

    So If anyone see the typo, point it out and I'll.. uh... try to fix it. :P

    And just in case, I also put extra steps and colored some to help the you guide through the problem with extra detail as possible.

    So... feel free to ask if you don't understand something.

    b303385b710d2c12bed7ff44402ebeef.png

    176d915871721a78f0fa756f9da557c8.png

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    14b4aeb1c3f29838db861375c213ecc5.png

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    If you already got the answer then consider this. Especially if you don't know what LIMITS are. It might help you understand a bit since this is a good example. You might have seen this in Algebra 2 and above.... well, I did at least...

    That's really close to 0.25. In fact, the infinite sum would result in 0.25.

    0a15d0285bcadd17c72f5b4dec2cb0fb.png

    In case you don't know limits, they just mean "as the variable in the function(equation) reaches for certain number (in this case, infinity)"

    The reason why I have 0 there is because any number divided by ridiculously large number will give you a number very close to 0. Therefore, 1/infinity will give you a number so small, we consider them as 0. and we can prove that already by looking at the original sum from n=2 to 100, which is very close to 0.25, but not close enough. if you try to do this with larger number other than 100, then you'll see that the number will never pass 0.25. That is the LIMIT of the equation.

    Now, if you like to think a bit deeper,

    Consider that

    S=1/1x2x3 + 1/2x3x4 + 1/3x4x5 + ... 1/98x99x100+.... 1/(n-1)n(n+1)

    Also, S=s+r where s is sum from n=2 to 100 and r is the remaining sum (from n=101 to infinity)

    You will see that the remainder will be just r=S-s.

    Why is this important when it is obvious?

    It tells us more that what we just see. But I'll just say that we can find an infinite sum that doesn't add up to infinity, as the limit tells us.

    • Upvote 2

  7. Posted · Report reply

    Been busy:
    Majority being College stuff - I literally had full packed schedule.

    Moderating a new forum my friend created - My other friend had older one that I moderated as well, but it got inactive so we made a new one with other guy... but it's also inactive. No members lol. We'll get there... hopefully. 

     

    Writing a story with another friend - Took the second majority of my time. Not much progress since my friend and I were busy and didn't really write stuff down... We're on chapter 3 right now... I'm looking for anyone who can help me edit later, but idk when that "later" is...

     

    I should get on here. I completely forgot about this place... I missed it so much too.

  25. Posted · Report reply

    What I really want is a headset.

    I do look for the sound quality it produces, but I am a bit picky about models too...

    I want it big enough to feel it wrap around my ears and heavy.

    why heavy?... that I'm not sure, but the heavier, it feels somehow better carrying them around my neck.

    ... please don't get the misunderstanding on the next one though...

    Another thing is this eroge called Koihime Musou.

    umm.. yes. 18+, H game... the story looks interesting, but the fact that it's an eroge makes it;;; quite impossible to get unless I order it from J-list... $50 is quite a lot a the state I'm currently in.

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