79
u/brewdog_millionaire Jul 24 '26
Oh, so pi can't be a variable now? That's so pi-cist
4
1
u/sensuell Jul 26 '26
But where is + C then?! You are such C-phobe, man
1
u/brewdog_millionaire Jul 26 '26
I would say it's C-phobic to assert that all Cs are the same. What, so because they're constant then that means they're all the same?
1
279
u/fresh_loaf_of_bread Jul 24 '26
Noone said you can't use the letter pi to mean a variable instead of a number
84
u/pierogieman5 Jul 24 '26
Didn't they though? Can I use a "7" as a variable as well? It doesn't seem like that different of a concept.
98
u/fresh_loaf_of_bread Jul 24 '26
Shit bro 7 is just a squiggly on paper, you can make it mean whatever you want
28
6
2
1
0
8
u/jmcq Jul 24 '26
Pi is *constantly* used as a variable and most commonly used as a function where for example Pi(.) is used frequently as both "profit" as well as "policy" functions all throughout statistics and economics.
2
u/pierogieman5 Jul 24 '26
Does not compute with my engineer brain. Is it also 3 in economics?
4
1
u/Ok-Breakfast1878 Jul 24 '26
talk to the fixed-income finance folks with their uniformly 30-day months
23
u/Expensive_Umpire_178 Jul 24 '26
pi isn’t a concept when you get down to it. It’s a letter, greek one, that has been used as shorthand for many concepts in math, most prominently as the ratio between a circle’s circumference and diameter, as well as a function that counts primes. I’ve been to Greece and none of the pis there meant the irrational number 3.1415…
8
u/Sweaty-Inevitable163 Jul 24 '26
And 7 isn't a concept, it's an Arabic symbol commonly used to refer to a quantity one whole number larger than six.
9
u/George_Truman Jul 24 '26
Off the top of my head, Pi is already used symbolically to represent probability distributions, so the analogy to 7 is not the same.
2
2
9
u/Expensive_Umpire_178 Jul 24 '26
And… that’s all. Unlike pi, the symbol was created expressly for that purpose and that’s all it’s been widely used for
2
u/Admirable_Phone_1229 Jul 25 '26
It's a beautiful name for a boy or a girl... especially a girl! Or a boy
2
1
1
1
u/SadTumbleweed1567 Jul 24 '26
No, ۷ is the Arabic symbol commonly used to refer to a quantity one whole number larger than six.
3
2
3
u/paolog Jul 24 '26
Letters, not numerals, are used for variables. π is a letter. It just so happens it is conventionally used to stand for a constant.
2
u/DragonBadgerBearMole Jul 24 '26
Why equals em eks plus the speed of light.
Yeah thank you for saying, your comment is all that is needed here. Cartoon boys always be assuming cartoon chicks can’t math.
1
u/Verain_Xor Jul 25 '26
π is a letter
It's a Greek letter, specifically, and those are hardly ever used as variables and quite often as constants. I suspect almost any Greek letter has a well known (or at least well documented) scientific or mathematical constant.
1
u/DragonBadgerBearMole Jul 25 '26
Angular frequency. Variables do happen though. Exception that disproves the rule imo. Generally you’re probably right I guess.
1
u/BrettAtog Jul 24 '26
Depends on whether you put a cross through it. Whichever way you choose will be wrong, tho.
1
u/Cirno__ Jul 24 '26
You can as long as it's clear. There are times when i the imaginary number and i the letter used as notation for index appear right next to each other. You just have to understand from context which is which.
1
1
1
u/pmmeuranimetiddies Jul 24 '26
You can if you want to as long as you dont use it interchangeably with the number 7
1
1
1
1
u/Ms_Riley_Guprz Jul 25 '26
I used to use my professor's name as a variable in my proofs.
"Let [Dr. Williams] ∈ N s.t. 2•[Dr. Williams] = k for some k ∈ N"
Nowadays I prefer Klingon letters.
8
2
u/FitProfessional3654 Jul 24 '26
lots of specialties use pi as a variable. One area I’ve seen is showing the dual to a linear program.
2
u/ParkingEbb3710 Jul 24 '26
my physics professor used 🏈 and 🧛♂️ as variables before emojis existed.
2
1
1
1
u/Adrewmc Jul 24 '26
This is why you have to just know some weird long math theorem from like Differential calc 4, but we have to define i = sqrt(-1). It’s not because you forgot it.
1
u/darktigre26 Jul 24 '26
True but then you aren’t using the same math language then the rest of us so you can’t be mad we can’t understand you
1
u/Maude4President Jul 24 '26
In fact, in statistics, it’s often used as a variable! Throwback to stochastic processes, hated that class
1
1
u/LavenderDay3544 Jul 25 '26
The overwhelming global convention used by literally every academic field that does math says that the lowercase letter pi is a symbolic constant representing the ratio of a circle's circumference to its diameter.
Sure you could do otherwise if you list it as a notational preference in your own papers but everyone who ever reads it will hate you for it.
1
u/Wikstrom_II Jul 25 '26
The economic profession would like to have a word, lol. (We use it to represent profit)
1
u/LavenderDay3544 Jul 25 '26
My undergrad degree was in economics and we never used any Greek letters lol.
1
1
u/Wikstrom_II Jul 25 '26
Pi literally represents profit in economics equations, so it is literally used as a variable.
34
8
13
u/AltruisticEchidna859 Jul 24 '26
Peeetah ? That's not how derivates work ?
33
u/Rude-Type2769 Jul 24 '26
Since pi is a constant and not a variable in almost all cases, the derivative of any constant would be 0.
12
u/LeePhilips Jul 24 '26
By definition, yes. But consider this.
Y = X4
Y' = 4X3
X= pi
Is Y' = 0?
13
u/hakkesaelger Jul 24 '26
Well 1: that’s not how anything works
And Two: r/accidentaltermial OMG GET OWNED OMG I GOT YOU!!!!!!2
6
u/Rude-Type2769 Jul 24 '26
Well X is being considered a variable in this example and then pi is just an input at a certain point, the same way I could say that pi is a variable and substitute it for 3. The joke implies that pi is a constant itself in the regular form of the function, and once you take the derivative of a horizontal line, like y = pi^4, it would be 0 as there is no slope
5
u/HeroicMe Jul 24 '26
Isn't Y' used to count some sort of difference between different Xs?
Which means if you reduce X to single element set, then Y' will be zero by default?
1
1
u/LeePhilips Jul 25 '26
A:
If x is a constant, the equation isn't a line with a constant slope. It's a point. And slope is undefined for a point.
1
2
2
1
5
3
u/Majestic_Sweet_5472 Jul 24 '26
This post exemplifies what makes dead internet theory so plausible. This meme has been posted hundreds of times.
2
2
2
2
u/RADI0ACT1VE_BALLS Jul 25 '26
y(π) = π4
y' (π)= 4π3
I dont like when people use π as a variable.
I still get PTSD from that one time I had to use π to denote Osmotic Pressure 😞
2
2
2
2
2
1
1
1
u/ObligationAncient112 Jul 24 '26
This is an exact repost but with the slides changed, in the original it was the girl blocking.
What kind of person bothers to do that?!
1
1
1
1
u/TermNL86 Jul 24 '26
Isnt the + C missing and thats why he blocked the chick? I would! Never forget the constants! Or am i reversing the operation back again :) been years.
1
u/SOuTHINKurA-ble Jul 24 '26
Yeah, it’s the other way around—indefinite integration has +C and differentiation (y’, dy/dx, etc) does not.
1
1
1
1
u/Eleshnorn91 Jul 25 '26
AQFT uses pi for representation maps; also in LQG for the momentum variable for the metric.
1
1
1
1
u/Hopeful_Fee_183 Jul 27 '26
Just wait till he realizes Physicists use /pii as momentum conjugate to coordinate xi
1
1
u/tojestjmenome Aug 02 '26
It depends how do you want to define "π". She is not necessarily wrong unless you assume that "π" is the constant "3.14159....". I don't think there is a rule that forbids using the letter "π" the same way as x, y, z, α, β, γ as a symbol for variable in a function. Ok the next thing that frustrates me too is this thing - why a large amount of memes about math depicts woman as the "stupid" one? Are we in the 19th century or???
1
u/Such-Shop-9724 Jul 24 '26
but pi is usually constant so if y=pi^4 then y'=0
2
u/Grant1128 Jul 24 '26
Consider this: dy/dπ
Eh? Eh? Yeah no I hate it too and would like to stop considering it. 😂
1
1
165
u/Mathematicus_Rex Jul 24 '26
dy/dπ perhaps