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On March 29 2014 07:55 MtlGuitarist97 wrote:Could someone explain why "e" is ~2.7? The way my teacher taught us to evaluate e is the lim x--->0 of (1+x)^1/x, or lim x ---> infinity of (1+1/x)^x. I'm only in an introduction to calculus course, don't make me feel too bad about myself 
Euler's number is 2.718 is just a number. It doesn't really have any physical property it relates to, unlike how pi represents diameter vs circumference of a circle.
For calculus, the reason e is useful, is because the derivative of e^x, as well as the integral of e^x are both e^x. This is a very useful property of e^x, and it is the only number that has the same derivative as the function. This function of it was special enough to warrant making a number for it. It doesn't have any physical meaning, like Reynolds Number for example, but it is pretty special because it shows up in math in many different topics, as well as economics.
Now because e^x has the same derivative as it's function, it is very very very useful to model exponential functions using e^x. The reason is, most function with applications in science and engineering are worked with. You need to take it's derivate to find it's rate of change, it's integral for other applications...
That's why when you make a function to model something, you will usually try to model it using this equation:
Value = B + A*e^(-kt)
Because then by taking it's derivative you get a simple:
Value Derivate = -k*Ae^(-kt)
Due to the simple property of :
f(x) = e^x
f(x)' = e^x
While a number different than e behaves as such:
f(x) = a^x
f(x)' = a^x*ln(a)
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Yeah, I knew how the derivative of e^x works, but I appreciate the explanations to both of you. Guess there just isn't a reason why e is equal to that, lol. My teacher was also explaining catenaries and how that's something like (e-x)(e-y) with different coefficients to represent the force of gravity acting on something (specifically he cited the shape of a telephone cable curving down due to gravity as being a catenary.
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Why do most anime series have a committee or council in the starting credits, what do they do?
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On March 29 2014 10:14 {CC}StealthBlue wrote:
Why do most anime series have a committee or council in the starting credits, what do they do?
Pretty sure it's just a name for the group of people who worked on the anime. An animation studio can have many different animes ongoing at the same time.
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Vodka storage for drinking. Should I put it in the fridge, freezer or a cupboard.
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Has anyone else ever bearcrawled up the stairs before? I sometimes do it when I'm alone
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your Country52798 Posts
The following is a true story, and SC2 related but doesn't fit in any of the simple questions/answers threads.
I was making a 2v2 map for the newly announced sc2 map competition and was using the rotational symmetry tool.
After I crafted the mains and naturals for one side I happened to glance at the opposite corner. The cliffs were the same but the ramps were rotated incorrectly.
I removed the ramps and tried placing them again, but they were again skewed. I made sure my map size fit the symmetry tool and it did. So there should be nothing wrong.
Just to check, I traced over all the cliffs and placed the ramps again. They were still wrong.
I saved and quit (in case the issue magically fixed itself) and started over. Just to be extremely careful, I kept the bounds exactly as I kept all of my other maps, used the same symmetry tool I always use, and started creating the same layout.
Fifteen minutes later, I realized that the symmetry tool was off… so, I turned it on and started tracing over the cliffs I had already created. The cliffs were created differently on the other side, no matter how careful I was. I quit this one without saving, and noticed that my previous attempt had mysteriously vanished. I started over on the same bounds but with different textures. Everything worked correctly until I started recreating the same layout. Suddenly, the cliffs stopped matching up and the ramps I placed were messed up again.
I restarted the editor and started again. I started making a layout for a 1v1 map but then added the second player and the other bases. Before I do this, I make sure that every single cliff is in exactly the right place. After adding the second player, I place a small cliff near the center (part of the 2v2 map) and it is incorrectly reflected on the other side. Again. All the cliffs I had previously placed were still perfect. I place a ramp on one of them and the entire cliff reflected on the other side changes drastically.
…
So, my question is, does this map that I'm creating have some malicious force driving it, and should I abandon it, or should I press on through any means I can and hopefully discover the cause behind this unusual glitch?
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ALLEYCAT BLUES51102 Posts
On March 29 2014 11:38 [UoN]Sentinel wrote:
Has anyone else ever bearcrawled up the stairs before? I sometimes do it when I'm alone
I have.
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On March 29 2014 11:38 [UoN]Sentinel wrote:
Has anyone else ever bearcrawled up the stairs before? I sometimes do it when I'm alone
Do it whenever I'm not at a public place, unless there's an awkward silence moment. Then I'll sometimes do it just to get a few laughs.
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On March 29 2014 10:14 {CC}StealthBlue wrote:
Why do most anime series have a committee or council in the starting credits, what do they do?
As I understand it they are the coordinators. They get the funds, sponsors, animators, voice actors, script writers etc from different places and make one product.
See them like a limited liability company. So if the product tanks nobody important is bankrupt.
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On March 29 2014 11:56 The_Templar wrote:
The following is a true story, and SC2 related but doesn't fit in any of the simple questions/answers threads.
I was making a 2v2 map for the newly announced sc2 map competition and was using the rotational symmetry tool.
After I crafted the mains and naturals for one side I happened to glance at the opposite corner. The cliffs were the same but the ramps were rotated incorrectly.
I removed the ramps and tried placing them again, but they were again skewed. I made sure my map size fit the symmetry tool and it did. So there should be nothing wrong.
Just to check, I traced over all the cliffs and placed the ramps again. They were still wrong.
I saved and quit (in case the issue magically fixed itself) and started over. Just to be extremely careful, I kept the bounds exactly as I kept all of my other maps, used the same symmetry tool I always use, and started creating the same layout.
Fifteen minutes later, I realized that the symmetry tool was off… so, I turned it on and started tracing over the cliffs I had already created. The cliffs were created differently on the other side, no matter how careful I was. I quit this one without saving, and noticed that my previous attempt had mysteriously vanished. I started over on the same bounds but with different textures. Everything worked correctly until I started recreating the same layout. Suddenly, the cliffs stopped matching up and the ramps I placed were messed up again.
I restarted the editor and started again. I started making a layout for a 1v1 map but then added the second player and the other bases. Before I do this, I make sure that every single cliff is in exactly the right place. After adding the second player, I place a small cliff near the center (part of the 2v2 map) and it is incorrectly reflected on the other side. Again. All the cliffs I had previously placed were still perfect. I place a ramp on one of them and the entire cliff reflected on the other side changes drastically.
…
So, my question is, does this map that I'm creating have some malicious force driving it, and should I abandon it, or should I press on through any means I can and hopefully discover the cause behind this unusual glitch?
Sounds like it would be less work to just manually recreate the symmetry than bothering with that tool any longer.
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On March 29 2014 11:38 [UoN]Sentinel wrote:
Has anyone else ever bearcrawled up the stairs before? I sometimes do it when I'm alone
Yes.
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On March 30 2014 05:14 Parametric wrote:
How do magnets work?
The spin of the outer electrons on iron, nickel, cobalt, gadolinium, neodymium and samarium atoms form up in one direction. This shows as a magnetic effect on other metal pieces of these types of atoms. (That is how I understand it.)
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In some metals(iron etc.) electrons can flow in small contained circuits. Magnetism is when very many of those mini circuits exist in a piece of metal. So basically it is electriomagnetism but it is innumerable many small electron flows.
That's how I understood it.
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On March 29 2014 11:23 Orcasgt24 wrote:
Vodka storage for drinking. Should I put it in the fridge, freezer or a cupboard.
Freezer if ur drinking it in the next hr, otherwise put it in the cupboard
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On March 29 2014 08:16 zJayy962 wrote:Show nested quote +On March 29 2014 07:55 MtlGuitarist97 wrote:Could someone explain why "e" is ~2.7? The way my teacher taught us to evaluate e is the lim x--->0 of (1+x)^1/x, or lim x ---> infinity of (1+1/x)^x. I'm only in an introduction to calculus course, don't make me feel too bad about myself There really is no reason e is ~2.7. That a rather silly question if you think about it. It'd be equivalent to saying why is pi = ~3.14.
What >.< No no no no no. Neither e nor pi is arbitrary! Pi is defined as the ratio between the circumference and diameter of any (every) circle. That's the *reason* why pi is ~3.14... because that's the constant ratio that's obtained from the two circle properties. (It can then, of course, be used in many other contexts.) The same goes for e (as I explain below); it's not merely arbitrary. It can be generated naturally! It's not only important merely because we have special derivatives for it (we really don't, actually... they're just special cases of some generic constant a).
On March 29 2014 08:26 FiWiFaKi wrote:Show nested quote +On March 29 2014 07:55 MtlGuitarist97 wrote:Could someone explain why "e" is ~2.7? The way my teacher taught us to evaluate e is the lim x--->0 of (1+x)^1/x, or lim x ---> infinity of (1+1/x)^x. I'm only in an introduction to calculus course, don't make me feel too bad about myself Euler's number is 2.718 is just a number. It doesn't really have any physical property it relates to, unlike how pi represents diameter vs circumference of a circle.
It absolutely does have relevant definitions and properties, especially seeing as how useful and naturally (get it?) it appears throughout mathematics. There are a few ways to generate the value for e (which explains why e ~ 2.7):
First of all, e is the sum- as n goes from 0 to infinity- of 1/(n!). This series is used throughout mathematics, in areas like statistical and probabilistic theory (the normal distribution formula and others) and generating other important identities and equations (like Euler's identity).
e is also derived through compound interest. Remember back in precalculus when you learned about those two "different" compound interest formulas, one for when you have a finite number of compoundings (monthly, weekly, daily, etc.) and the other for the continuous compounding situations (A = Pe^(rt))? Well, the latter is a special case of the former, when the number of compoundings n approaches infinity (hence compounding "continuously"), and a key value forms as n approaches infinity, which asymptotes at the maximum amount one could obtain via compounding: the value of e.
There are other derivations as well, and many places where it's useful to use e or derive formulas containing e... but those are two reasons why e is exactly what it is.
EDIT: Number 1337 Reply. Woot.
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I was looking at this picture made for Steam:
http://imgur.com/a/woQcK
What kind of tools should I use to make this kind of "info-pictures"? Anyone got recommendations? I am thinking of making some of these myself.
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Does teamliquid not have a diablo 3 subforum anymore? I've spent more time than I'd like to admit searching for up to date D3 threads and haven't found any.
Considering that RoS has come out and the game is actually fairly playable with loot2.0/nomoreAH I was surprised that noone has really been posting about it on TL.
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EPT
