Ridiculous Notation and Conventions

same

File: 1467697002570.jpg (11KB, 213x231px) Image search: [Google]

11KB, 213x231px

>>8186085

Oh, and the use of "It can be clearly seen" or "It is fairly obvious" in any textbook ever. It's the laziest cop out WRYYYYYY

>>8186085
>REEE
gb2/r9k/ you fucking autistic cancer.

> 99% of the notation in differential geometry. Standardise that shit already.
go and complete your doctorate by doing so.

none of what you mentioned pisses me off as much as putting a space after greentext arrows

>>8186085
>The official name of our moon is "The Moon"
>The official name of our sun is "The Sun"

>>8186135
keke

>>8186085
>99% of the notation in differential geometry. Standardise that shit already.

What isn't standard?

>sin^2(x)=sin(x)*sin(x)

>sin^-1(x)=arcsin(x)

>>8186143

In my experience, every author picks a notation they find most convenient. Which is totally fine, but a bit disorganized.

>>8186170

>this

I always write asine or acos, fuck that negative exponent B.S

Writing the formulas of conic sections not in standard form. Like really, why make me do some completing the square/factoring bs?

>>8186170
>^-1 being the inverse or the reciprocal

Agreed. It looks like bad math. If ^-1 was used consistently, sin^-1(x) should be csc(x)

Anything that is called normal, regular, or prefect in math. We need more Grothendieck's naming shit.

>>8186273
I've seen texts where sin^-1(x) is asin and sin(x)^-1 is csc(x)

I see many authors in biological literature alternate between cytoplasmic and cytosolic as though they're equivalent but they're really not.

Molality is a fucking stupid unit.

And this isn't a notation really but lack of one - nobody respects the capitalization of SI units. I see ml everywhere when it should properly be mL. And fucking using u instead of [math]\mu[/math].

And before you ask why it matters - what is mm? is it millimolar, or millimeter? what about mg? milligram or milligauss? Yes, of-fucking-course it's always obvious from the context what you're talking about, but the point of units is that they should be an unambiguous notation. If you have to resort to inferences from context to figure out exactly what the unit is, the nomenclature is fucked.

>>8186242
>>8186273
You are both retards. I bet you write f^2(x) to mean f(x)*f(x).

>>8186135
Technically it's Sol for our sun, hence Solar system and star system for all the other systems.

d/dx

gay as fuck

>>8186085

> The charge of an electron being denoted as negative, leading to "positive charge flow" in circuits and other retardation.

Electricity does not work the way you think it works.

>>8187870
>He doesn't use Yuler notation
[eqn]D(ie)[/eqn]

>>8186085
I hate grading partial fraction problems because kids don't factor by powers of x and solve with a matrix

>>8186085
People who use one letter in different fonts for different objects which are related to each other, e.g. [math]A,\mathfrak{A},\mathcal{A}[/math]

Anything in modern type theory, get your fucking shit together and stop using all kinds of triangles in your statements and ten different enviroments, all in different cases and fonts.

People using more than two '

>>8186471
>but that's what sin^2(x) means anon

>>8186111
TRIVIAL
R
I
V
I
A
L

>>8188002
It's a function. It should adhere to the established notation for functions.

>>8188063
Ah, yeah I misread you before. Yeah the sensible thing would be sin(x)^2 and asin(x) = sin^-1(x) but meh...

>>8187882
The direction of the electric current is defined in the direction in which a positive charge would flow, not in the direction the electrons actually move.

When the CO2 cannisters are empty, doctors in the pharmacology building where I work will stick a note on it for the janitors, but they all write "MT" instead of "empty." I asked about it, and two confirmed that that is what it means. Drives me crazy.

BEDMAS

I'm shocked at how many people confuse or think that multiplication comes after division and that kind of thing. Apparently in Europe, they might do it a bit differently than Americans and Canadians, though I haven't verified that.

Why the hell do addition and subtraction come before multiplication and division anyway? Did some autistic "intellectuals" just suddenly decide that that is the how it should be or is there an actual reasoning that can be demonstrated in the real world?

>>8188083
sin^2 is sin*sin
sin^2(x) is (sin*sin)(x) = sin(x)*sin(x)

>>8188345
why not just sin(x)^2 = sin(x)*sin(x) =/= sin(x^2)
Sin^2 notation may just be a lazy way of drawing less parenthesis but it creates confusion as it appears as an operation applied to an operation. I dislike it.

>>8188357
sin(x)^2 is ambiguous. are you talking about sin((x)^2) or (sin(x))^2?

it's not a lazy way to draw less parentheses. functions form a ring with well-defined sum and product.

>>8188326
You can't really be this stupid. Tell me you're joking.

>>8188362
But everybody writes sin(x^2) if that's what they mean.

>>8188345
That's retarded and also wrong. You can't multiply two functions, you can only compose them.

>>8188362
>f(x)^2 is ambiguous. are you talking about f((x)^2) or (f(x))^2?
This is you. This is what you sound like.

>>8188326
It's useless once you understand what all the notation of standard operations actually means.

>>8188374
You can multiply functions when you get past babby-tier math.

>>8188397
You can only multiply functions evaluated at a value and even then only of the image has a multiplication defined on it.

>>8188405
here's the lowest level example i could possible find

https://www.khanacademy.org/math/algebra2/manipulating-functions/combining-functions/v/product-of-functions

They're pretty understandable/concise when you're used to it, but lots of notations/symbols used in standard QFT gets pretty wild.
>Dirac delta
>kronecker delta
>functional derivative
>variation in a function
>delta as a variable itself
>implicit indices on virtually symbol you write down, typically several kinds of contractions implied by juxtaposition of symbols.

File: Eagle-Kitchen-Extension.jpg (680KB, 1936x1296px) Image search: [Google]

680KB, 1936x1296px

>>8188326
Are you retarded?

Do you understand that division is defined in terms of multiplication? You can do them in any order because multiplication is associative.

[math]\frac{a}{b} \equiv a \cdot b^{-1}[/math]

Have you ever heard of the distributive law?

[math]a \cdot (b +c) = ab +ac[/math]

If you want to have precedence order to save your hand from writing parens, distribution pretty much makes the choice of operation order obvious.

When you rely on stupid mnemonics to understand rather than just plain ole understanding, you tend to show your lack of understanding. Understand?

>>8188405
Of course you can multiply functions. You sound sad that composition and multiplication are two different things. Why?

Composition:
[math]f(g(x)) = h(x)[/math]

Multiplication:
[math]f(x) \cdot g(y) = h(x,y)[/math]

>>8188427
You are literally retarded.

When you have f:A->B,
f is a function
f(x) is a function evaluated at x (it is an element in the image of the function.

(f*g)(x) is syntactic sugar for f(x)*g(x). You are never multiplying the functions themselves, only elements in their images. Furthermore, it only makes sense when there exists a multiplication in the codomain and both functions share the same codomain.

For instance I can have continuous functions between topological spaces without algebraic structure (no addition or multiplication).
f:A->B
g:C->D
Then what the fuck is f*g?
What the fuck is f(a)*g(c)??

There is a different notion called a categorical product but in the context of category theory exponents always refer to composition and inverse.

>>8188459
he's dug himself into a semantic hole after getting irrational upset at the idea of sin^2(x) popping up all over the place in virtually every field of science and existing as a well-understood/agree-upon notation.
I wouldn't worry too much, friend.

>>8188464
i never said multiplication between any two functions is always defined

it is still multiplication of functions

you are attempting to be a pedantic brainlet and failing

>>8188475
No it's not. Multiplication of functions would give you a new function. Multiplication of elements in the image is just that.

Suppose
f:A->B
g:A->B
h:C->D

Then fill in the question marks
f*g:?->?
f*h:?->?

>>8188464
You are using a lot of big fancy words there, bob.

>>8188459
Tell that to /b/. When it comes to math, some of those guys are fucking retarded.

>>8188492
when you multiply, for example, polynomial functions, you get a new polynomial function

When people use "~" to mean "is proportional to" and "is approximately". My prof in statistical thermodynamics used to do that and it drove me nuts. Especially since there are alternate notations you can use for both that can't be misinterpreted.

>>8188520
>polynomial functions over a ring
You are multiplying elements in the ring, not the functions themselves.

>>8188583
let's multiply elements in the ring since you insist the functions themselves cannot be. let h(x) = (f*g)(x). what is h? why are you incapable of admitting that there exist cases in which f*g = h?

>>8186085
I can't stop laughing at this image.
Fuck. The rate that 4chan generates shit like this never ceases to impress.

>>8188568
I do that.

>>8186170
More generally f^{-1} for inverse function. But I can't recall another notation

>>8188464
>(f*g)(x) is syntactic sugar for f(x)*g(x).

Disagree. The first is a function evaluated at x, the other is the product of two functions evaluated at x.

(fg)'(x) is not syntactic sugar for f'(x) g(x) + f(x) g'(x)

File: 1466865621981.jpg (26KB, 500x500px) Image search: [Google]

26KB, 500x500px

>>8188612

>>8186085
but electrons are negative

>>8186111
>it is fairly obvious that the sky is blue
REEEEE COP OUT

>>8188464
lol moron

>>8189201
lol moron

>>8188607
yeah I don't know why this one in particular is making me giggle like a highschool girl

>>8186170
I'm completely comfortable with this notation but it really doesn't make any god damn sense.

The whole imperial system.

>>8188464
You are a special kind of stupid. Do you know what you get when you take f(x)*g(x) for all x? It defines a function, which we call f*g.

>>8186085
>biochem
>thousands of common names used instead of systematic names

It makes sense for complex molecules, but why can't we just call pyrovate 2-oxopropanoic acid?

Also, acetic acid should be called ethanoic acid.

>>8188453
fuck don't even get me started on qft bullshit

>The charge of an electron being denoted as negative, leading to "positive charge flow" in circuits and other retardation.
Babby can't tell left from right, how cute.

>>8186246
It's really easy to identify the similarities and differences between the conics and their components (foci, vertices, etc.) when you write them in their respective, easily identifiable forms. I'd rather really understand the relationship between a hyperbola's directrices with respect to it's centre than memorise a bunch of "the conic is a hyperbola if A>0, C<0, or A<0, C>0, B=0. the conic is an ellipse if A, C>0, B=0. the conic is a parabola if..."

a big part of notations and names in topology

>>8189262
nah no one calls it ethanoic acid except for high school nerds trying to sound smart. go look at any paper in an org chem journal and you'll see it called acetic acid, and its salts acetates

>>8189388
I never said it's not called acetic acid. Better learn to fucking read, brot.
Using systematic names for simple molecules would make everything easier.

>>8189411
Fuck you, you said "acetic acid should be called ethanoic acid", which is stupid because everyone already calls it acetic acid and knows what that means. Similarly for pyruvate and many other molecules with common names. Everyone's going to look at you funny if you say "2-hydroxypropanoic acid", but everyone knows what "lactic acid" is. It's just easier to use common names for all but the simplest molecules. Dumb cunt.

File: top nep.png (401KB, 500x708px) Image search: [Google]

401KB, 500x708px

>>8189262
>2-oxopropanoic acid
>willingly using IUPAC
>even once
kek

>>8189425
fuck you fucker fucking cancerous fuck

File: math.gif (19KB, 443x364px) Image search: [Google]

19KB, 443x364px

How come nobody has brought up mathematical notation? Z and Q for example, let alone all the bullshit like pic related. It should just be called Autism notation. It has nothing to do with math, and everything to do with Autism.

The misuse of e.g. mibi vs mega for computer systems is frustrating. At tibibytes, 1 terabyte is only .93 tibibytes.

The million different syntaxes for programming are beyond the scope of this post.

>>8186466
Mol and Meter are SI units, there's no distinguishing even with caps.

>>8188300
And electrical movement was defined before electrons were. Electrons are negative by being opposed to positive (default) fields. The reasoning is backwards.

We should be more frustrated with anode and cathode.

>>8189505
meter is supposed to be lowercase m, molarity is supposed to be uppercase M. the official SI symbol for mole is "mol", no abbreviation.

It's all quite unambiguous.

>>8188497
>some

>clopen

>>8189508
yeah I'm not sure why people are confused over M, m, mol, and mol dm^-3. you'd have to be real dumb to have trouble over this

>>8189508
>supposed to be
You realize the poster got pissy because "Liter" should have a capital L right? It's retarded and nonsensical to have one of the "prime" units, the "Liter", be capitalized, but "meter", not. Rename it the Mol if you want it to be capital, otherwise stop making up even more nonsensical naming schemes.

>>8187902
It's Euler you retard.

>>8188792
That is also syntactic sugar. In any higher mathematics fg always refers to function composition but it's too hard for babby-math people who use ' for derivative.

>>8188603
>let h(x) = f(x)*g(x)
fixed

This is hardly function multiplication in any sense. All of your functions must have the same domain and codomain and the codomain must have a multiplication for this to even make sense. In this special case you could claim you're defining a multiplication between functions but you're really only doing anything in the codomain.

The definition falls apart as soon as you start changing the domain, codomain, or allowing the codomain to have less structure (i.e. if your functions are just continuous functions from one topology to another, each lacking any algebraic structure).

f and g are sets of order pairs. In particular if [math]f\colon A\to B[/math] then math]f\subseteq A\times B[/math]. When you write f(x) as a polynomial you're evaluating f for arbitrary x. Functions in general are not nearly this well defined (unless you're just working in babby-math).

>>8189644
jesus just fuck off already

BRA-KET notation in quantum mechnaics. I bet they invented it becouse it would be too simple without it.

>>8189623
You do realize >>8189508 and >>8186466 are the same person, right?

Me. I'm that person. Those are my posts.

>>8187858
Actually, the name "Solar system" uses "solar" as an adjective, just like "solar wind" and "solar panels". If you lived by another star, you could call your star system "the solar system" and you would use "solar panels", not "Kepler panels" for example.

I'm not just saying this because of the "Solar system" part. The IAU officially accepted "The Sun" (capital S), "The Moon" (capital M), and "The Earth" (capital E) as the names for these three celestial bodies, until the aliens tell us what they named them.

>>8189505
I find the mispronunciation of "giga" to be even more frustrating.

But mathematical notation is not as autistic if you understand what it says. The propositions stated there are core axioms that define our arithmetical system. The kinds of proofs like your picture are the ways we connect logic to math, so there is a lot of notation that must be used. When you run out of Greek, Arabic, and Hebrew letters and numbers, I think it's better to create new notation rather than new symbols. Every new symbol you create has to have a typographical index, which just makes it even worse to actually write down.

>>8189668

Check out https://youtu.be/7zI5zsPuRVs?t=1h21m46s , Schuller destroys the notion of bra-ket notation. Skip to 1:36:10 if you get the general gist of the notation and want to hear him really demolish the idea.

>tfw I'm still constrained to using bra-ket notation because of convention and because I work with physicists who have never rigorously proved anything in their life

>>8189654
this

looking at the riemann curvature tensor makes me want to die

>>8189946
looking at diff geo proofs using coordinates makes me want to die

>>8189654
>>8189938


status: SO TOLD

>>8190115
There are cases when index notation reduces complexity of the expressions (in the technical sense). Just objects and concatenations of each other makes some stackings not possible and then you must introduce additional operations to get the same thing that an index summation does.

>>8189505
Z is Zahlen, i.e. numbers. Where's the problem?
Ring is also a German word, which besides "ring" as in "wedding ring" also denotes a group ("Verbrecherring"). So it's like "group".

In electrical and computer engineering, [math]\sqrt{-1} = j[/math].

I know that I is taken but why the fuck did we decide to use it for current?

>>8190314
nah bro I is intensity
hehehehe

>>8190314
The reason why engineers use [math]j[/math] is to prevent confusion with what you people already define [math]i[/math] and [math]I[/math] with.

File: ByH4jKW.jpg (104KB, 960x720px) Image search: [Google]

104KB, 960x720px

>>8190339
That's the story everyone is fed, but if you do any EM, you'll know that [math]\vec{J}[/math] is in fact already defined as a volume current density, a more general concept than line current [math]\vec{I}[/math]. In fact, past basic electronics, I [math]never[/math] use [math]\vec{I}[/math].

Engineer's are fucking insufferable sometimes.

My contribution to the thread is spherical coordinates. Goddamn, I swear literally every permutation of coordinates has been standardized across all fields, be it math, physics, engineering, etc.

The mathematicians have their heads up their asses because the standard ordering of the coordinates does not yield a right handed coordinate system.

The physicists have their heads up their asses because [math]\theta[/math] should be azimuth like it is in polar coordinates.

The engineers make the same mistake that the physicist make.

Alas, why can't we use the labels mathematicians use, while still respecting right handed coordinates?

>>8190381
you can thank the earth's rotation and the fact that civilisation developed in the northern hemisphere for the way [math]/theta[/math] (the math version) is defined

>>8190477
FUCK I hate latex, [math]\theta[/math]

>>8189425
LOL calm the fuck down kid. I am not disputing that everybody knows what acetic acid is, I am just saying it would be better if there were less common names to be memorized when the systematic name by itself is clearly short enough.

>>8189748
>The kinds of proofs like your picture are the ways we connect logic to math
Do you mathematicians actually enjoy that stuff? I read a bit about it in some book once and it bored me to fucking tears.

File: giphy.gif (480KB, 493x342px) Image search: [Google]

480KB, 493x342px

>>8188374

>>8189541
Ok, as dumb as that is what other short term would you use? Having open and closed not be opposites was naturally a dumb decision though.

>>8191276
Is there a word for a set that is neither open or closed?
It seems more common than either open, closed, or clopen sets.

>>8187858
No it isnt, real life isnt a sci fi novel

>>8186435
>csc(x)
triggered
>>8187870
>>8187902
Liebniz notation is superior retards

>>8190314
guess what
[math]\omega[/math]

>>8191208
People come up with common names because it's easier if you need to repeatedly refer to something. For someone coming into the field yeah, maybe systematic names are easier if you've had experience with them. But for someone working the field, using common names is quicker and more convenient.

>>8188568
Actually "~" means "asymptotically equal". E.g. Sequences an and bn are in the ~-relation if lim (n-->oo) an/bn=1.

>>8191451
>Liebniz notation is superior retards
t. high school kid who never dealt with any differential equation ever.

>>8192307
>butthurt mechanical """engineer""" who can't handle few more characters

newton fucks can go fuck themselves

>>8187870
Agreed, only time it's even remotely useful is implicitly, but even then there should just be a different variable than dy/dx fuck

>>8189436
Take your pedophile cartoons back to >>>/a/.
Fucking degenerate.

>>8189444
What does this post have to do with science, dumb fucking weeb?

>>8186466
>>Molality is a fucking stupid unit.
I hate most of the notations used in chemistry, but nothing angers me more than normality.

>>8189436
IUPAC is the best system I can think of, the problem is no one cares about it.

>>8186085
(a,b) instead of ]a;b[ for open interval

>>8189436
IUPAC is awful, once you get beyond simple structures it is abysmal.

>>8193073
But what else can you do?

>>8186111
>the proof is trivial and left as an exercise for the reader

>>8189189
I also do that, what are the alternate notations that you speak of? I would like to be better.

>>8193107
[math]\propto[/math] and [math]\approx[/math]

>>8193088
It's a troll.

File: Untitled4.png (35KB, 654x451px) Image search: [Google]

35KB, 654x451px

This

>>8189644
>acting this high and mighty
The space of functions that map into a certain algebraic structure has its own algebraic structure. For those kinds of spaces the use of powers makes sense.
It doesn't really matter that it doesn't hold up for the general case, math is context dependent.

Your comment about 'syntactic sugar' is also bullshit, you can define functions pointwise.

You will fall down from mount stupid soon.

im triggered in general by the structural formulas of things like azides or other compounds with multiple resonance structures contributing to reality

but thats a limitation of 2d drawing i guess

nobody really has a good way to draw an azide group

I have always hated theta and used phi instead.
I know, I know.

>>8188002
Namefags don't know how to greentext.

>>8188374
What exactly do you think function composition is algebraically?

>>8193287
Chemical bonds are not exactly reality either.

Lewis structure has a lot of shortcomings. But it works well enough and we know about the inaccuracies.

>>8193379
What the fuck do you mean chemical bonds aren't real? What actually happens on the atomic or molecular level?

>>8186085
It's stupid that we have to write parentheses to show the structure of formulas. It would make way more sense if we wrote down all the different parts on SEPARATE pieces of paper and then put them in corresponding Tupperware containers to indicate the structure.

>>8193088
draw the fucking structure

File: 1369563957663.jpg (39KB, 500x667px) Image search: [Google]

39KB, 500x667px

>>8193393
I think he refers to the fact that the electrons don't have fixed positions or rotate on shells around the nucleus. They are described through orbitals which are basically probability density functions. They give you the probability to find an electron at a certain position around the nucleus. And once you start looking at multiple atoms, molecules and so on it gets really, really complicated.

File: glass peebles.png (695KB, 2000x1360px) Image search: [Google]

695KB, 2000x1360px

>>8186085
>>8189193
>eletrons are negative even though they aren't empty spaces, which by common sense should be regarded as "negative particles"
>eletrical current is not used as the direction where the eletrons are going because of positive conventions

Why? Was this made just to intentionally make physics harder to understand or just to complicate it at the cost of hystorical conventions? Shouldn't science be pratical instead of making unneded messes like this? Is this ever going to be fixed?

>>8193436
But how do you call it? I was thinking about it and I can't come up with something clearer than "Bicyclo[2.2.1]hept-2-ene" for example.

>>8193678
Well in this specific case I'd use the common name, because anyone I need to communicate this to should already know what norbonene is, or failing which they can easily look it up. In other cases it really is easier to just draw the compound, label it 1/2/3/A/B/C etc. and just say "compound A", or to be more specific, ketone 1 or acid 3 or oxazolidinone 22.

Resorting to subscripts instead of just using a different character.

Using subscripts n and m.

Using subscripts i and j

Using lowercase l (ell) for ANYTHING.

Using nu and curvy v and regular v.

Putting a comma after an equation, before a line-break back to the text. The equation is not supposed to be part of grammar. That's why it exists separately, outside of the blocks of text. The transition back to paragraph structure accomplishes the grammatical role of a comma anyway. Things that are not part of the equation do not belong in-line with it, with no space between them. This can be especially problematic because it can look like ' ("prime") on characters in the denominator.

When people call the "proportional to" symbol "alpha".

When people call lowercase epsilon "script E".

When people draw exaggeratedly large serifs on their greek letters.

Big rational expressions formatted as being multiplied by a single number or character, when said number or character could easily fit in the numerator, e.g. (8x/z)*y where (8xy/z) would be appropriate.

Putting extra stuff in the numerator only to have it cancel out every time, just for the sake of fitting everything in one rational expression, e.g. (2n+1)/2 where n+(1/2) would be appropriate.

Starting calculus courses with limits. It's like starting teaching someone to drive by explaining what forms of ID they'll need to get a title transferred to their name.

4's that look like 9's.

5's that look like S's.

2's that look like Z's.

2's with an exaggerated curly-q.

7's with a cross-bar (absolutely degenerate).

>>8193051
Couldn't disagree more. Parentheses and brackets are supposed to come in left - right pairs.

>>8193820
>Resorting to subscripts instead of just using a different character.

using different characters when working with sequences?

yeah great idea, genius, you fucking moron

what a poseur.

>>8189631
I think he was making ebin joke about its incorrect pronunciation.

>>8186085
Euler's identity is way more prettier with [math]\tau[/math] instead of [math]\pi[/math].

[math]e^{i\tau} = 1[/math]

>>8193051
no this is a garbage suggestions

>>8193820
>Putting a comma after an equation, before a line-break back to the text.

Properly written mathematics should read like any writing you'd find in any science book, except now we require [math]\text{numbers and symbols}[/math] in our prose. Sometimes the expression or relation you want to make reference to does not fit inline, without causing unsightly spaces or breaking in the middle when you reach the right margin. For this,[eqn]\text{we typically set the expression on its own line,}[/eqn]both drawing attention to it via negative space and giving it the room it needs to be formatted properly.

In principle you can read the expression in words, though often it's too complex to actually articulate in e.g. spoken English. That said, since it is actually a phrase of the sentence, it requires a comma, and the only typographically reasonable place for a comma to go in that scenario is after the expression.

>>8193858
*it will sometimes require a comma

>>8189631
>not spelling it Oiler so you remember how to pronounce it properly

0.999999... = 1

No, it does not equal. 0.9999.... does not exist. Actual numbers like 1 exist. Potentials like 0.999... do not.

>>8194502
that's the funny thing no one seems to ever get.

you cant have imaginary numbers like 0.999

in reality things only exist as 1's and 0's. numbers greater than 1 are just convenient ways we have created to depict this rather than a combination of 1's and 0's.

0.999 is an impossibility. there can never be anything other than whole numbers.

0.9 =/= 2

File: 2016-07-09-211026_493x60_scrot.png (9KB, 493x60px) Image search: [Google]

9KB, 493x60px

Most mathematical writing. Sometimes I think they should just write in code.

[code]
(defn freq [w] (count (filter (partial contains? w) A))"
[/code]

>>8194551
>not wirting note.js
XDDD
(u(r(gay)(:;;();

>>8187916
>matrix for partial fractions
Oh fuck me. That's so obvious, but I've always solved it the stupid way.

>>8194563
get off this board you code monkey

>>8186170
Agreed, it should be consistent function notation.
[eqn]\sin^2(x)=\sin(\sin(x))[/eqn]
[eqn]\sin^{-1}(x)=\arcsin(x)[/eqn]
[eqn]\sin(x)^2=\sin(x)\cdot\sin(x)[/eqn]
[eqn]\sin(x)^{-1}=\csc(x)[/eqn]

File: 1460338000938.jpg (350KB, 1164x1164px) Image search: [Google]

350KB, 1164x1164px

>>8192336
Ok I laughed. But first of all:

1.) I'm a chemistry student
2.) Leibniz notation looks fucking ugly unless dealing with partial derivatives
3.) Literally noone uses Newton's notation, I have zero clue why you included that. If it was bait, I guess it was decent enough to get me to bite, I'll give you that.

>>8194702
> Literally noone uses Newton's notation
Newton's notation is amazing for having a bunch of functions all with the same independent variable...say in physics with time.

Leibniz is awful and the only time it's not is when dealing with the chain rule (where it's an abuse of notation)
Euler is autistic, which I kinda dig; much like using square brackets for cross products and angle brackets for dot products

>>8194725
>Leibniz is awful and the only time it's not is when dealing with the chain rule (where it's an abuse of notation)
It's a feature of the notation, not an abuse of it. I like it in certain contexts; it's more similar to the definition of the derivative than the other notations.

>>8192336
>>8194702
> noone uses Newton's notation
I guess noone's heard of the Euler-Lagrange equations.

>>8193393
It's a troll.

File: sdfaasdf.jpg (7KB, 300x279px) Image search: [Google]

7KB, 300x279px

>>8186135
Well it's better than "The Star"

>>8186085
>life begins at conception

>>8195755
Beginnings are social constructs.

>>8195755
Then when does it begin?

>>8195763
Time is a social construct.

>>8195768
Kek.
But seriously, from a scientific stand point, when does life begin?
I've seen stuff posted about how embryology text books say it begins at the moment of conception, with this quote thrown around a lot ""Almost all higher animals start their lives from a single cell, the fertilized ovum (zygote)... The time of fertilization represents the starting point in the life history, or ontogeny, of the individual." from Carlson Patten's Foundations of Embryology.
But I was just reading a thread where some med eng. anon said that "The starting point, the earliest stage of life, not a formed, living, human being." in response.

Any anons with knowledge on the subject know which is correct, and why?

>>8195784

It really depends on what you are trying to say by "life". Life if just something that ticks off a list of criteria for something to be considered "alive". Technically speaking, life DOES begin at conception, since the embryo can now reproduce among other things, making it a living thing. Most people who spout this fact are trying to use it to pander to people who subscribe to the idea that "all human life is valuable, and by killing a living embryo you are by extension killing a human being, which is bad."

>>8195840
>>8195784
Life begins before conception, both the sperm and the egg are organic life.

You'd be better off asking where it became human, but then you're even further into arbitrary land.

Best to go back to the old days, and say it isn't ensouled until it takes its first breath. Things were so much simpler that way.

>>8186085
tl;dr so idk if this was mentioned earlier but base 10 pisses me off. Base ten literally gives us repeating decimals for no goddamn reason, makes everything containing the number 3 a headache, and gives us unintuitive halves/quarters/etc.

Imagine if we had base 12. No significant changes to our number system, except literally everything is so much easier.

>>8196033
how's first year CS going?

>>8196033
I hate this "base 12 is better" meme. Just like τ and π the difference in clarity is marginal.

>>8189505
"Conventional current" is such bullshit. I can't believe it survived the era of vacuum tubes.

>We should be more frustrated with anode and cathode.
Throw out "anion" and "cation" with them. We need a rule of not making students memorize unnecessary terms.

>>8187923
That reminds me of fucking trig...what was it? Capitol letter for side and lower case for angle, then using the same fucking letters (like the sides are A, B, C, then the angles are a, b, c--i really suck at handling certain kikind of labels...sorta dyslexia but not (yes diagnosed professionally) and this shit would wreck me, almost failed my first trig test because I just kept getting lost trying to solve a single triangle. I didn't realize what was going on and thought I didn't understand the process until I saw one labeled differently and had zero problems with it...simple solution from then on was label the fucker myself).

Also, physics, stop with the fucking subscripts. Once you put a second subscript on something, you're fucking up.

>>8188326
>bitching about order of operations without understanding them.
Not even once

>>8188568
In algebraic logic, it means not

>>8197701
multiple subscripts and superscripts have special meaning in physics. They're basically mandatory when dealing with tensors.

>>8193559
Because Ben Franklin chose to call the wrong one negative and by the time we figured that out, it was too late to easily change.

>>8189644
But how can we verify that those cohomologies converge along the axial torus?

Along the smooth manifold I mean

>>8196033
base 12 would be just as bad, regarding anything containing the number 5 or 7

prime numbers always a bitch, man, no matter what base

and there's no way to make a base that accounts for every prime number

>>8198586
I don't think trying to get as many primes as possible is a bad thing either.

Base 12 has lots of good qualities, but I think switching may be pragmatically quite senseless, since 10 is not the worst choice.

>>8198592
just to account for 3, 5, and 7 would require a base 105
which seems a bit absurdly large for a numerical base to me, but hey apparently there were ancient ass sumerians and shit that made base 60 work so who knows

>>8198601
Base 60 is quite nice, yes. As long as it's not something like base 7, I think it will not be absolutely terrible, so while eg. base 5040 or 360 might be superior in certain terms, even if it was practical, switching to it doesn't really save anything, and is more trouble than it's worth, since base 10 (or base 18 or something similar) is not really that terrible.

>>8186085
>The use of π rather than τ. Seriously, what the fuck is this?
The choice of τ for better π annoys me, I already use it for time constants.

>>8193834
except tau stands for a billion other things other than 2*pi.

>>8195784
well, it really depends on wether you're pro-choice or pro-life.

>>8196033
might as well use base 60 at that point. The bigger the base, the more digit symbols you need, the bigger the risk of misreading.

>>8197701
>Once you put a second subscript on something, you're fucking up.
Then how the fuck do you deal with multiple indices?

>>8199074
like "e" but, don't bother, tauists are never pious.

>>8197701
you're too retarded to use math

>>8186111

>the proof of this theorem is left for the reader to discover :^^^^^^^^^)

>>8193820
>When people call the "proportional to" symbol "alpha".
>When people call lowercase epsilon "script E".
lol
>When people draw exaggeratedly large serifs on their greek letters.
me
>Starting calculus courses with limits. It's like starting teaching someone to drive by explaining what forms of ID they'll need to get a title transferred to their name.
Wrong. How else do you teach the definition of a derivative without at least a hand wavy definition of a limit?

>>8193051
hahahahah point and laugh
>>8194593
>Agreed
>says the opposite
although he's retarded and I agree with your definitions.

f(x)=y

Functions are different than variables

>>8200247
thank you very much for your illuminating reactions, fucking tripfag

>>8200247
limits are the most intuitive thing i've ever encountered in maths. git gud.

>>8200425
They are the first unintiuitive thing that I ran into studying math.
Now, they're old hat for me

>>8200425
Engineer detected.

>>8186085
Still laughing at this goddamn thing days later.

>>8193858
This. Considering equations as part of the text is actually considered the formally correct way of doing things. I do it and for the most part I like it but I do feel like there may be other styles worth exploring.

After doing a bunch of formal logic, type theory, and category theory I've come to the conclusion that programming and proof writing are really two sides of the same coin. However when code is embedded into a text it isn't included as part of the text's grammatical structure. I think a proof writing style worth exploring would be something akin to literate programming.

https://en.wikipedia.org/wiki/Literate_programming#Example

>>8193820
>Not crossing your z's
>Not crossing your 7's

>Using lowercase l (ell) for ANYTHING.
This is only a problem if you write your 1's as a vertical line with no serifs.
>Putting extra stuff in the numerator only to have it cancel out every time, just for the sake of fitting everything in one rational expression, e.g. (2n+1)/2 where n+(1/2) would be appropriate.
There's some semantic information you're butchering by restructuring the expression.

>Big rational expressions formatted as being multiplied by a single number or character, when said number or character could easily fit in the numerator, e.g. (8x/z)*y where (8xy/z) would be appropriate.
This annoys me too but in some (typically applied) contexts it can make sense. See above.

>>8193204
>You can do things.
>Not in general you can't.
>But it works in some contexts! That means it's okay to say it works because if it doesn't then people will just know I wasn't talking about their context.
lol, okay sure. All rectangles are squares.

>Your comment about 'syntactic sugar' is also bullshit, you can define functions pointwise.
That isn't the issue. The issue is that fg doesn't work that way in general. It isn't part of the common notation. As such in some contexts one may create some syntactic sugar that allows them to write more concise notation that only makes sense in that context.

i.e. This is syntactic sugar:
"Since all of our functions are well behaved then we can adopt some notation that will help clarify the concepts at hand:
[math]fg=\{(x. f(x)*g(x)) | x\in A \}[/math]
where [math]f\colon A\to B[/math] and [math]g\colon A\to B[/math] and [math]B[/math] has a multiplication (group, ring, etc..)."

>>8198583
Clearly I was talking about simple topologies on finite sets.

>>8200410
They're not though

>>8199174
>he doesn't use Cantor's pairing function

>>8200413
>butthurt that I told him his idea was stupid

>>8200425
I think we're talking about epsilon-delta anon
>>8200442
Yeah they are just something you have to sit down and get done. To not include them in a course on fucking calculus is retarded.
>>8200565
I love writing reports where the equations and maths read like prose. It just feels so nice and fluid reading it back.
>>8200410
wat

>>8193820
>Resorting to subscripts instead of just using a different character.
makes sense most of the time, since it indicates that the variables are of the same type.
For example E_kin E_pot etc.
If you mean x_1,..,x_n have fun finding new characters beyond 3 dimensions
>Using subscripts n and m.
>Using subscripts i and j
what exactly is the problem other than maybe i looking too much like j?
>Using nu and curvy v and regular v
I agree. When taking notes I always have to make it really obvious, which one is meant, otherwise I'll confuse myself later on.
If it's TeXed lecture notes I don't mind, since the distinctions are pretty clear.
>Putting a comma after an equation, before a line-break back to the text. The equation is not supposed to be part of grammar. That's why it exists separately, outside of the blocks of text. The transition back to paragraph structure accomplishes the grammatical role of a comma anyway. Things that are not part of the equation do not belong in-line with it, with no space between them. This can be especially problematic because it can look like ' ("prime") on characters in the denominator.
I don't agree on that. Equations are part of the text and should have proper punctuation. Never seen anyone using - ("prime") on characters in the denominator - anyways.
>When people call the "proportional to" symbol "alpha".
>When people call lowercase epsilon "script E".
Never heard of that in my entire life.
>When people draw exaggeratedly large serifs on their greek letters.
Whats the problem there?
>Big rational expressions formatted as being multiplied by a single number or character, when said number or character could easily fit in the numerator, e.g. (8x/z)*y where (8xy/z) would be appropriate.
Sometimes you have more important variables, that should be singled out for readability.
Example: Differential equation (a/2c) y'' + (d/5b) y = 0 is better than ay''/2c+dy/5b

>>8201023
>I think we're talking about epsilon-delta anon
There are a lot of words, but it really does an excellent job capturing this intuitive idea of becoming arbitrarily close. I think it's worth mentioning in an intro calc course, along with a very thorough discussion of the ideas accompanied by pictures, for the sake of getting some idea that we can make the notion precise.

>>8189623
>liter
>meter
You cancerous shit-eating piss-for-brains.
litre and metre

>>8200044
REEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

>>8201252
Non-native English speaker here: whenever there are different spellings present in dialects, the one with less correspondence to pronunciation is considered more sophisticated, and thus preferable?

>>8200602
Context does matter though. If A is a ring, then Hom(A,A) is also a ring and you can multiply the functions. If you want to state composition you should write [math]f\circ g[/math] anyway.

>>8201301
>>8201311
>>8201314

Usually (especially with an official French term like this, created by the French BIPM), it is preferable to spell things the official way and not the American way. Americans just spell shit however they want for no reason and they're so hard-headed about it that plenty of English words now have a "European/International" spelling and an "American" spelling. Sometimes this is just a matter of preference/locality/history, such as color or colour, but in this case, litre and metre are the official spellings. (See chapter 2 here, http://www.bipm.org/en/publications/si-brochure/)

(Deleted previous post to fix capitalization and quoting)

>>8201317
>Americans just spell shit however they want for no reason
The pronunciation of "metre" is /ˈmiːtə(r)/, not /ˈmiːt(r)ə/, at least if you pronounce the 'r'. Isn't having the phonemes in the same place as letters a reason enough? I mean, it's not like about any European language other than English or French does that.

>>8201326
>spelling should be completely determined by pronunciation and not have any rules, or take etymologies and historical spellings into account
Oops, I mean
speling shood bee cumpletle determind bi pronunsiashin and not hav ne ruls, or take etimoloGs and historicul spelings in2 a count

>>8201326
just accept that the english language is a clusterfuck of inconsistencies
>>8201330
>strawmanning this hard

>>8201334
>fallacy fallacy
I'm making a valid point.

>>8201339
you make a valid point against an argument, the poster you're replying to didn't make
congratulations

>>8186466
>"Molality"
Fucking This. There are much better ways of quantitatively describing a substance than the amount of fucking moles of solute per kilogram of solvent.

>>8202335
It is funny when you have a Japanese guy in your intro to chem class and he's having massive issues differentiating between molality and molarity.

>>8189262
I've always wondered why we just don't call it Ethanoic Acid.

File: Untitled.png (19KB, 519x381px) Image search: [Google]

19KB, 519x381px

>>8202340
Because we're just saying "vinegar" in french.

>>8202335
The primary advantage of using molality as a measure of concentration is that molality only depends on the masses of solute and solvent, which are unaffected by variations in temperature and pressure. In contrast, solutions prepared volumetrically (e.g. molar concentration or mass concentration) are likely to change as temperature and pressure change.

>>8186466
>I see ml everywhere when it should properly be mL
IUPAC says it can be both, and I'm pretty sure l is more common for liter. Either way, liters are not an SI unit, [math]\mathrm m^3[/math] are. Or, [math]\mathrm {dm}^3[/math].

>>8186274
Grothendieck used lots of normals and regulars, but I suppose only because they were established terms in the old theory.

>>8193820
>curly-q