#competition-math
1 messages Β· Page 25 of 1
But thank you anyway
Unfortunately school is not letting me do those things
much homework
Happens
Lol
Got a 85/150 on a gauss prac. contest
π
Its only grade 7
*skill issue for my partHAHAHA
What is it ?
Nah don't worry, it doesn't mean you're genuienly bad at maths
Something you juste do worse than you thought you would do
A wide range of past CEMC contests and their solutions to familiarize yourself with the contest format, level of difficulty, and problem solving strategies.
These are like introductory math comp. problems
I started grinding on the first one
I'll grind the other one later
because the entire day I have been grinding NT-Prealgebra on alcumus lol
We will never know if you don't try
How is this competition maths?
Or it's just an end of school exam
Or something
But ok
You have like an 1 hour for all the questions
So it kinda makes sence
Nah bro, i got freaking spanish first XD
Wait they have computer comps ???
Like coding programming and cs stuff ???
Imma do that too then, thank you even more for those links
lol
Yeah
Competitive Programming in terms of what people say
:D
Honestly, its best to ask them lol
One thing about them is that... I do not know where to submit them
because they give you data sets that you to put the inputs in
so yeah
Oh, and incase you didn't know, @topaz mist , they have these Problem Gens
You can have like your own contest-style
I find it fun to just print problems and simulate an actual math contest environment HAHA
Oh, cool there are some other stuffs here, too
I should make like a list of these types of resources
That's so cool
Could it just be trainings or archives of real life comps ?
Ty, I'll look that up elsewhere too
I don't think so?
Well if you can't submit them use it as self awareness of your current level ig
Those are nowhere near the level of amc
disagree
AMC is hard for the grade levels they are testing
so students need easier questions to review the foundations and build confidence
CEMC isn't as easy as you claim if you're practicing towards AMC
click on PCF and Euclid
It's nowhere near Polish Junior math olympiad
I mean at least like 99% of questions I guess
Idk how other olympiads are like
Im talking about this
.
AIME questions are easy, aren't they?
Iirc
Ok
They are not
But some old AIME questions are easy
For sure
No
Accualy they are easy
At least some of them are
Some of them are for sure
Like "Jimmy walks a kilometers per hour he takes a break for b hours, and it takes him 420 hours to get to home, but if he was 10 km/h faster he would get to home after 2 hours"
Seems like an easy system of equations
you haven't seen q20 to q25 on the AMC
and you haven't specified which AMC you're talking about
you should compare with AMC 10 to be honest
early aime yes could be easy
late aime is not easy
K
oh wait is the Polish junior one only up to 8th grade? my bad
True
these are pretty standard for AMC 10 not 8
but then AMC 10 is the first round of qualification
so you're comparing apples to oranges
It's for 10th graders?
For math and music nerds
yes
10th grade and below
but yeah AMC is a different format, all multiple-choice
this is cute
regardless if you just look at the material covered by each question
you'd have to compare this to the AIME, I see
yeah it's hard to compare
For what grade is AIME I?
Oh
It's I
My bad
lol
yeah so generally 10th to 12th grade
K
I wonder how hard is Polish MO finals in comparison with USAMO finals, probably trivial lol
I mean of course not all questions
Because Poland isn't bad in olympiads
We have a lot of silver medalists on IMO
And they often fail to do some of the questions on the last round of the olympiad(I mean at the time of the contest)
that's normal
well if you can only choose 6 people from each country
the countries with the highest populations will have an advantage
Or the countries that adopt people from other countries
Sorry I had to
And of course I also have to post the memical photo
That is probably like 10 years old or something Idk
This thing is funny
6th question
1/216 people got it
Well accualy he didn't
There was a mistake in his proof
Or it was not enough
Or some other story like that
I haven't seen it
I've just heared the story
"incomplete gamma function"
this is the international chemistry olympiad...
ah yes
american olympiad team
Then even better
But some IMO teams were also mostly asian
You can try
If you want to
There are infinitely many primes so yea no?
So
n = 1; 3
So n can't be dividable by two, it's not always a prime neither a composite
Ok 5 and 9 don't work either
11 neither
Ig n = 1; 3
And it's not a proof
It's 3 then
Uh
It's probably 3
But I can't solve it
And I don't know anyone who can
So it's probably 3
It's 3, we already solved it
Yes
But we don't know all the numbers that work
Mega Angelo13 and Sebastian GΓ³ral solved the problem
Wait
You are the one who created the question
Nah
You just showed it to us?
It's from another server
Problem solved β
I mean it was created because some dude chcecked that it fails for a lot of n, to he thought "ok probably only 3 works" so he sent it to some other dude, he couldn't solve it so he sent it to another server, and we couldn't solve it, so it's unsolved lol
Nah
It's "find all p that work"
You have no proof that there is no other p that works
It was checked up to 3000 first prime numbers or something around that
And so far only p=3 works
But there is no proof
At least for now
There is no calculator that can prove if some number p is a prime number above 13
Not in the web
And I am very angry if the number is like 1836829229833664829102873646472992991938473930192747920287373837
Wolfram Alpha can't solve it either
heuristically probably, cus sum 1/log(n) log(n^n + 2) converges
um i don't see a good way to prove this
are you sure this is solvable?
if this is just from exploration & ur unsure if this is open or not, it may be worth posting to #advanced-number-theory and seeing what ppl know abt it
Nah
Because people there asked me "why do I care about it?"
And I don't have a reason
I mean I'm just curious
It isn't important to any mathematical reaserch I'm aware of, or something
basically if the question is solvable, then there'll be like factoring trick or like some modular arithmetic trick that you can do
but there doesn't feel like much you can do, so i'd imagine the problem's open
cus basically every problem regarding "are there infinitely many primes of the form X" is unsolved
Probably
But Idk
why do we care that there are infinitely many primes?
why do we care about infinitely many 1 mod n primes?
ultimately like there is no real practical application
just say like u were curious what we currently know about primes p s.t. f(p) is prime
I'm just saying what people told me on #advanced-number-theory
Modular arithmetic does not work
I mean in some cases the smallest divisor is like over 100000
But it might have some factorisation
I mean it seems to have some factorisation
Because it seems to be divisible by something of size near to p^2
But it probably does not work
I don't know any polynomial that would work for a lot of cases
Or anything like that
yh i doubt it
you can probably use sieve methods to bound the number of primes with this property <= x
actually ur bound's probably gonna be kinda awful
anyway plugged this into wolframalpha and got an answer of ~2 so yeah we probably expect finitely many primes of ur form
Also where does the sum come from
I mean Ik that prime number theorem
But where exacly
It's like "assuming p^p+2 is a random number"
Or something like that
And then we sum the probabilities of a number of some number of that form being prime?
model each number n as having a 1/log(n) chance of being prime
then find the expected number of primes
Makes sence
Also
It has to be of form 6k+5
Because modulo
Shouldn't it be a sum of 1/ln(ln(n)(n^n+2))?
I mean
n^n+2 because the form of the number
and ln(n) because prime number theorem
?
log(n) for probability of n being prime, log(n^n+2) for probability of n^n + 2 being prime, assume the events are indepedent & multiply them together
ultimately it doesn't really matter too much cus this is just a heuristic that says there's probably only finitely many of them
true
Also we should sum from like n=10000
Or something
I mean it was checked for first 3000 primes
Ye wolfram is not enough
LOL
But we probably can something that "statisticly around 0,01 of a number is prime" lol
I mean it probably is lower than that
But like what's the point of heuristic arguments like that?
We know that n^n+2 is not random
LOL
ad hoc heuristic arguments are why mathematicians believe i.e. there are infinitely many mersenne primes but not infinitely many fermat primes
pleasure to meet you mathematicians
K
Cool
ok
is that (r^r) + 2
the vast majority of us are students or other people interested in maths
and not professional researchers
i love maths
but im buns
clazz is always boring bc its js stuff i know
so ion like class
tbh
the teacher gives us friggin packets
its unbearable
what are you learning
does anyone have resources on how I can prepare for the AMC12
the actual calculation is nice, the concept it easy to grasp. its just the explaining
oh like dilations and stuff?
im in ninth grade π
why are you still learnign that in 9th grade
that's like 7th grade stuff
no offense ofc
i dont know, the curriculum here in canada is different
winnipeg to be specific
i do logs
π
im joking
but i attempted to learn logarithms, i was trying some exponential equations that utilise in natural logs and whatever
yeah i know im annoying, math js excites me
the mistake here is thinking people learn things in a specific grade 
ur not (:>
i wasn't trying to be mean
middle school topics vary a lot in terms of timing
people here come from all over the world yeah
they might mean this by 'scale factor'
yes we use, SF = diagram / actual
ah true so on a map
then are you asked to find the real-life area of something on the map?
yes
damn okay you're doing IGCSE confirmed
i dont know what that is lolzers
oh interesting
that's what 9th and 10th graders study in the UK + many international schools
yes so the very important thing is (area ratio) = (length ratio)^2
yez
also like keep the ratio order the same, so large/small for both, or small/large for both
yeah
this is actually related
(volume ratio) = (length ratio)^3
like you know a cube has three lengths being multiplied right
length * width * height
so all 3 get multiplied or divided by the length ratio
that's why it's ^3
nice
hey so if you want extra practice material by any chance
for your maths in school
check out: https://mrmannmaths.wordpress.com/home/igcse-extended-maths-0580/igcse-extended-revision-by-topic/
hell yah
ty
LMAOOO
we arent learning this
its too advanced for the ppl in my classroom
Rocket Revise Instagram CAMBRIDGE (CIE)IGCSE MATHS (0580) Topical Papers Compiled by Ahmed Gul Paper 2 Paper 4 Topical Questions PAPER 2 Number Upper & Lower Bounds QP Currency & Conversion QP Rounding & calculator QP Ratio QP Simple & Compound Interest QP Percentages QP Maps and Scales QP Upper & Lower Bounds MS Currency & [β¦]
yeah it's definitely challenging for this grade level
think you might enjoy it though if you have any free time
yes lolzz, i am looking forward towards it
this one girl in my class is doing piece-wise functions
wow
yeah that's like precalc
all of this maths you learn in school comes really handy for contest maths also
if you don't know a broad range of topics for your year level
you won't even get half the questions right
so trueeee
to be fair competition problems are hard in their own way
but people ask how do I get better at the AMC? what should I study?
a lot of maths is freely accessible online
whats AMC?
that's why I point students towards the UK curriculum
IGCSE then A level mathematics
it's the American one
ohhh
first round of olympiads
hey, i think you should give me a hard math problem fs
enjoy suffering
what continent are you in?
Oceania
if you are excited about math i think you will enjoy AMC
thats so far π
its like australaisa i believe i learnt that
yeah but that's outdated
we should be together with all the Pacific islands
only makes sense
yes
Aus + NZ + all these islands = Oceania
then that makes us a real continent
a real continent hidden under the sea for large parts
(Zealandia is the 8th largest continent, cause a lot got sunk over and only New Zealand and a few other islands remain)
ohhhhhh
i had this friend
who moved to asia
he was talking about the continents but he didnt include oceania π
thats js amazing
i am so determined to solve ts
i am setting up my parameters
the center of each smaller circle lies on the circumference of the larger circle
this looks like that one maths problem i did
but its different bc it had
this means that the distance from the center of the large
r
circle to the
center of any smalelr circle is simply gna be R (radius of the larger circle)
and each smaller circle has a radius of r (each smaller circle)
do i need to
oh wait nvm
bro how do i get the relationship between R and r π
@ornate blade sorry for pimg
ya man i give up im chopped
whats the answer
can we play hot or cold
is the answer between 5 and 9
wait
idk
π
R = r + r(sqrt(2)/2)
R^2 = r^2(1 + sqrt(2)/2)^2
squaring sides
ya i aint doing ts
fck it
I want to know the answer too now π
What's weird is that there are 4 small circles that are useless
Looks like fun
Sup
How do you guys increase your stamina in solving problems?
I just solved a really hard problem and my stamina got drained
It was this problem in NT/Prealg thata drained it haha
ah an alcumus question
not often that we get those
that sounds odd, are you sure you didn't just level up or smth
and/or are you possibly confusing this for your "accuracy" stat
What do you mean by this?
Yes, but those type of problem I get are in the hard difficulty that's why its a bit challenging
why specifically uk?
is it harder or something like that then other curriculums?
Let radius = r. ||Radius of smaller circle is cr where c = 1/sqrt(2). Area of intersection = area of two sectors - area of two triangles. Angles subtended at the centres = 4 arcsin(c/2), 2 arccos(c/2) = 4 t, pi - 2t, say. So area of intersection = r^2/2 (4 t + (pi-2t) c^2) - r^2 sin(2t) = r^2 (2t + (pi/4-t/2) - 2 sqrt(7)/8) = (3t/2+ pi/4 - sqrt(7)/4) r^2. So pi r^2 - 4(that) = (pi - 6t - pi + sqrt(7)) = (sqrt(7) - 6t) r^2 = 48pi||. I give up (and this is probably terribly wrong too).
yea, i gave up pretty quick
If anyone has any ways on how to self study calculus please let me know thanks
No need to ask βCan I askβ¦?β or βDoes anyone know aboutβ¦?ββitβs faster for everyone if you just ask your question! See https://dontasktoask.com/
You need very low technology to do well, especially compared to say AMC/AIME/USAMO
wdym low technology
Doesnβt need lots of theory to solve the questions
sure
Competition math, huh? Find every x:
βx + x = x^2
Which numbers solve this equation?
x^3 - 2x = x
guys im 8th grader what should i use to study for amc 12 i can only get 40
far too basic to be a competition problem
thereβs no depth or sophistication needed to solve this at all
18
did u check it π
gauth ai vs poe.com vs chatgpt
vs flying_fly
who do you trust more
idk humans are better
lol π
ai is under dev
so its hard to deicde with 4 diff answers
how did u find this asnwer
it's $\sqrt{\frac{48\pi}{\sqrt7 - 6\sin^{-1}\left(\frac{\sqrt2}{4}\right)}}$
flying_fly
more or less what this guy said
!nogpt
Please do not trust ChatGPT or similar AI tools for mathematical tasks, as they often generate output which "sounds correct" but has numerous factual or logical errors. Use of these AI tools to answer other people's help questions is strictly against server rules (see #rules).
if you need an online calculator to check your work just fucking use wolframalpha or smth not this ai slop nonsense ππ
is anyone here
solid foundation
not necessarily, but it's challenging in a way that is also accessible
also during a year you'd study across algebra and functions, geometry, trig and vectors, stats, and calculus in later year levels
it's probably the best organised curriculum among all Anglophone countries
well not many people know about the Irish Leaving Certificate, or New Zealand's NCEA which are also solid
those may be a bit harder to find materials that are not provided by the exam board
If I'll be honest, I don't even use WolframAlpha since I do not understand how it works. I often use ai to help me understand mathy-stuff and when it comes to the answer/solving part, I just let it explain the solution to me :PPP
you're doing yourself a MASSIVE disservice.
Let me clarify
when it comes to the answer/solving part, I just let it explain the solution to me
It's where I either got a correct/incorrect ans to a problem
it doesn't actually know what it's doing
it's just "hmm what do i think is the next word" :clueless:
At this point, I don't even know what PhD people do with o1 to help them with these sort of stuff
Can we come to an agreement that everybody has their own form of preferences?
Whether ai or not haha
you're very mistaken if you think that any PhD students use AI to explain the maths to them
they consult books and papers!
they ask their fellow students, or arrange to meet with their supervisor!
they always have sources based on real experience and knowledge, and not something generated by a predictive text algorithm which can't tell you where it got that exact info from
(AI is famous for hallucinating and generating made-up references)
exactly
there's always real people and materials that real people have written
gpt is HILARIOUSLY bad at anything even slightly beyond the surface level
all my profs and lecturers said that GPT sucks balls at writing essays
it doesn't really know how to answer a question and tailor its knowledge, or to write an extended response
it just rambles about the general ideas that the question touches upon
which is why AI search is good if you want to get a surface level understanding, a summary
but it sucks for anything any deeper
Just ask this discord server for help is better than ai
Alright, thanks!
Alright chat, I need clarifications
Let p = prime
What is the largest prime factor of p!
Would it be p itself?
Oh, nvm, I have made the correct assumption
yea lol
bruh
Besides that. gpt does not have any kind of creativity or problem-solving skills, he is just going always to opt for solutions way harder than should be and brute forcing operations with massive numbers
Like this question, I remember asking for chatgpt how to solve this problem and he always tried to compute 2024Β³, dividing stuff by 2024Β³
Let x and y be real numbers such that x + y = 2024 and xy = 8. If
1/xΒ³ + 1/yΒ³ = p/q,
where p and q are positive integers that are coprime, what is the remainder of p - q when divided by 5?
(A) 0 (B) 1 (C) 2 (D) 3 (E) 4
I remember asking chatgpt a simple inequality question
And it gave me some calculus solution
Which I cannot even verify
Here is the question
Prove that
Triaengle
o3 is really good at closed ended questions but not in open-ended and proofs I tried several competition proving problems and it gave the wrong answer for most questions
its 1 right?
!showwork
Show your work, and if possible, explain where you are stuck.
hint: ||use binomial expansion, then manipulate the terms a bit to get the term in the expansion of another binomial||
I tried that but I am a bit lost
I need to find where I solved a question, I will open a help channel
could we try induction?
idk but i'm sure that that won't be simpler than a direct proof
Actually it is 4
Idk I need help
There's a cool way to solve this due to polynomial symmetry
we know that $\frac{1}{x^3} + \frac{1}{y^3} = \frac{x^3 + y^3}{(xy)^3}$
hiidostuff
well maybe youve already solved it
idk
then we have that $x^3 + y^3 = (x + y)^3 - 3xy^2 - 3x^2y = (x + y)^3 - 3xy(x + y)$
hiidostuff
Yeah, that is how I solved it
nice
Is this called polynomial symmetry?
well
the type of polynomial tricks youre using is due to the fact that everything expands to a symmetric polynomial
a symmetric polynomial is a polynomial of x_1, x_2, ... x_n that remains the same no matter how you permute the variables
so for example, x^3 + y^3 = y^3 + x^3
turns out that every symmetric polynomial of x,y can be expressed in terms of simpler elements of x and y
that being (x + y) and xy
awesome
fr
shameless self promotion time
https://drive.google.com/file/d/1f_QI_U3iip--oyRnggvLf-Wt2W9yvquL/view problems from a contest we just hosted at usc
im getting A
is that right
or just reverse it
1/x+1/y=2024/8 and 1/xy=1/8
I checked again, the correct answer is indeed E
I can show if you want
Anyone here done the euclid?
its 4
each term in the numerator is divisible by 8 so p/q is an integer
then (2024)^3 / 8 = (1012)^3 which is 3 mod 5
then 3(8)(2024)/8 = 3(2024) which is congruent to 2 mod 5
wait i mightve screwed up
it's 129553457/8
no wait it is A
Im getting A
how?
the numerator is 1 mod 5
and p/q is an integer
therefore its A
bruh
Hmm
I get denominator is 3 mod 5
Specifically it is 8
thats irrelevant
i should say, when you reduce the rational expression, the numerator is 1 mod 5
Huh
I get that p/q=11232021/8
Numerator 3 mod 5
Denominator 3 mod 5
Why
you should get $\frac{(2024)^3 - 3(8)(2024)}{8}$
hiidostuff
its ok tho
from here the problem is pretty easily solvable
firstly, reduce the expression
Yes of course
to get $\frac{(1012)^3 - 3(2024)}{1}$
hiidostuff
The problem itself is not hard
Which numbers work for
2^n - 3 = prime number?
(finite answer)
Maybe im wrong, my attempt is just $n > 2$ where n is prime
Shawn
frick my punctuation is bad
Try so, there is a finite amount of numbers
What are we looking here for? What do you mean by finite amount of numbers?
Is there some kind of constraint?
like 3 < n < 9999?
There are several numbers which, when used, you get a prime number
1 < n < 100
In that area
Oh, then, its just {3,5}
Oh, wait
nv,
I just brute forced it and disregarded the prime numbers for n
My bad
Since if $2^n - 3 = prime$, then we check the numbers that're less than 100 for $2^n$.
Simple brute force should do the trick.
n=2:
$2^2 - 3 = 1$ (Not prime)
n=3:
$2^3 - 3 = 5$
n=4:
$2^4 - 3 = 13$
n=5:
$2^5 - 3 = 29$
n=6:
$2^6 - 3 = 61$
Therefore, the numbers for n are: {3,4,5,6}
Shawn
Why did my brain think that the bold text thing whould work for TeXit
Not only
What do you mean?
I mean these are not all the numbers to make a prime number
$\frac{1}{x^3} + \frac{1}{y^3} = \frac{p}{q} \Rightarrow \frac{x^3 + y^3}{(xy)^3} = \frac{p}{q} \Rightarrow \frac{(x + y)^3 - 3xy(x + y)}{512} = \frac{p}{q} \Rightarrow \frac{2024^3 - 24 \cdot 2024}{512} = \frac{p}{q} \Rightarrow \frac{2024(2024^2 - 24)}{2^9} = \frac{p}{q} \Rightarrow \frac{253(2^6 \cdot 253^2 - 8 \cdot 3)}{2^6} = \frac{p}{q} \Rightarrow \frac{253 \cdot 2^3(2^3 \cdot 253^2 - 3)}{2^6} = \frac{p}{q} \Rightarrow \frac{253(2^3 \cdot 253^2 - 3)}{2^3} = \frac{p}{q}$
samuel
$p = 253(2^3 \cdot 253 - 3) \quad \text{and} \quad q = 8 \Rightarrow 253(2^3 \cdot 253 - 3) \bmod 5 = 3(3 \cdot 4 - 3) = 2 \quad \text{and} \quad 8 \bmod 5 = 3 \Rightarrow 2 - 3 = -1 \Rightarrow -1 \bmod 5 = 4$
samuel
$p = 253(2^3 \cdot 253 - 3) \quad \text{and} \quad q = 8 \Rightarrow 253(2^3 \cdot 253 - 3) \bmod 5 = 3(3 \cdot 4 - 3) = 2 \quad \text{and} \quad 8 \bmod 5 = 3 \Rightarrow 2 - 3 = -1 \Rightarrow -1 \bmod 5 = 4$
yangbegeflex
$p = 253(2^3 \cdot 253 - 3) \quad \text{and} \quad q = 8 \Rightarrow 253(2^3 \cdot 253 - 3) \bmod 5 = 3(3 \cdot 4 - 3) = 2 \quad \text{and} \quad 8 \bmod 5 = 3 \Rightarrow 2 - 3 = -1 \Rightarrow -1 \bmod 5 = 4$
$x^3 + y^3 = (x + y)^3 - 3xy^2 - 3x^2y = (x + y)^3 - 3xy(x + y)$
yangbegeflex
dude this cool
nice
this is a channel for discussing contest math
- for linear programming problems, consider #linear-algebra or #optimization
- for testing LaTeX code, consider #bots or #latex-testing
if you need help in proving the inequality that you've proved, then you need to show your work
otherwise, you may try approach0 to search that
Approach Zero: A math-aware search engine.
I want to prepare for Math competitions
But I donβt have a routine
Any recommendations?
For Summer.
aops books to beginwith
Iβll just do it through YouTube
I have a study strategy that might help
Active recall strategy
Ok
Im a Sophomore
juust start one and stick to it
shouldnt you learn precalc first π
Yeah both
alsocalc does not matter for comp math
Thatβs what I mean
What matters?
Its just to build foundational knowledge to recap on basic skills
its rly different than school math
I think itβs helpful
pickup like aops volume 1
are amc questions good for other olympiads
im not condoning this but you may or may not be able to find the books free online
ehh
like which amc questions should i start with
amc is good if you are in the USA
Use YouTube
See how others practice
ok
Yeah
thanks
Yo can anyone help with this problem? Let ABC be a triangle in which we have drawn the median BE from vertex B, and a segment that goes from C to a point D on side AB. This point D can slide along side AB.
The intersection point of both segments is point F.
We call p the ratio between the segments into which D divides side AB, q the ratio between the segments into which F divides the median BE, and r the ratio between the segments into which F divides CD.
What will be the ratio between triangle CEF and triangle FDB for any value of p?
I'm pretty sure it's pr/2 but I don't know how to prove it?
Picture?
There
Ok
I honestly donβt know where to start.
Wait
So
The only thing I know from previous parts of the exercise is that r = p+1
I know weβre told that
CF/FD IS 7
So
If the triangles
Share the same height, the ratios of their areas is the ratio of their bases.
That being said
Yeah
I might need more info
Are you sure this is the question?
Yes, it is. Maybe you have to do it through Menelau's theorem, the other parts of the exercise were done with that
Ok
Also, BF Γ AD = 2 Γ FE Γ BD if that helps
Yeah thanks
Im reading the theorem to refresh memory
I just need heights and
Other ratios
Knowing AD/DC doesnβt help me determine the other segments
@warm mantle
So the problem doesn't say anything about the heights or the other ratios, but maybe you can find an auxiliary point parallel to AE in the FDB triangle and then say CEF is congruent to FDX and maybe something with that afterwards idk
Ok
It's a website in Spanish
It doesn't say the answer
I dont have the link but I can send screenshots
It's the 9th question
Oh
mass points
for this type of geometry problems involving ratio of segments and areas, you may want to use the area method to make your solution organized
.
<@&268886789983436800> here too
hx62d
<@&268886789983436800>
who does math and code at the same time in lua
hopefully, sending files like these isnt a violation. its like vector mathematics in lua, its a simple module and i plan on integrating quaternions
if its a violation then the mods can delete this
using roblox as a refence lol
It is not
But here isn't really the perfect channel to send that, focus on olympic maths here
#1213610885277421588 Would be a better channel
lollll
I revisited an old post: #1190382943663816756 message
Actually, L3435 showed a simple proof by rearrangement inequality in AoPS: https://artofproblemsolving.com/community/c6h1712301p11047177
The strategy is to start by homogenization of the given inequality using the constraint.
Inequality's LHS degree = -1
Inequality's RHS degree = 1
so use the "degree 2 = degree 0" equality constraint to raise inequality's LHS degree by 2 (by multiplying by "1")
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
1
ok idk what the point of this question is
but as a hint, consider $(\cos \theta+\sin \theta)^2$
Civil Service Pigeon
$(\sin\theta+3\cos\theta)^2=0=\sin^2\theta+6\sin\theta\cos\theta+9\cos^2\theta$
lumi
,tex \sin^2\theta+9\cos^2\theta&=-3\sin2\theta \ (\sin\theta+\cos\theta)^2-2\sin\theta\cos\theta+8\cos^2\theta&=-3\sin2\theta \ (\sin\theta+\cos\theta)^2&=-3\sin2\theta+\sin2\theta-8\cos^2\theta \ \therefore\sin\theta+\cos\theta&=\sqrt{-2(\sin2\theta+4\cos^2\theta)}
lumi
Compile Error! Click the
reaction for more information.
(You may edit your message to recompile.)
can i say this?
Recall that $\theta$ is a real number, then $\sin\theta + \cos\theta \in \mathbb{R}$. By contradiction, if $\sin2\theta+4\cos^2\theta$ is non-negative, then $\sin\theta + \cos\theta$ is part of the complex plane, which is not possible. Hence, \underline{\underline{$\sin2\theta+4\cos^2\theta\leq0$}}.
lumi
I was intending for you to consider $(\sin \theta +\cos \theta)^2$ in general
Civil Service Pigeon
This is fine though
this isn't my favorite wording
Since $\theta$ is real, $\sin \theta+\cos \theta$ must also be real. Hence, $\sqrt{-2(\sin 2\theta+4\cos^2 \theta)}$ must also be real, which implies that $$-2(\sin 2\theta+4 \cos^2 \theta) \geq 0$$ $$\sin 2 \theta+4\cos^2 \theta \leq 0$$
Civil Service Pigeon
cause the part about "is part of the complex plane" is a bit iffy
just say it's non real if you're gonna say that
the other issue is that you never excluded the possibility of the $\sin 2 \theta+4 \cos^2 \theta$ being zero
Civil Service Pigeon
hahaha
maybe i'm missing something but what is the point of the expression at the top
and what is part ii even saying
,w sin 2x + 4cos^2 x, x = pi
,w sin x + 3 cos x, x = pi
take that as you will
There is some $\alpha \geq 0$ such that $$\cos^2 \theta-\sin^2 \theta=4 \alpha \cos \theta$$
Civil Service Pigeon
Anyway r u good now
yep thank you pigeon

i think i remember you
from like 2 years ago
got to national and scored a zero hahaha
im proud of it tho
Although $\frac{\cos^2 \theta-\sin^2 \theta}{4 \cos \theta}$ isn't always non-negative
Civil Service Pigeon
so maybe they just want you to find the value of this in the case where it's non negative
and they're calling that alpha

not my favorite wording
in which case it would be ||sqrt(2/5)||
i may be missing something, but doesn't $\sin\theta + 3\cos\theta = 0$ already imply $\cos^2\theta = \frac{1}{10}$?
flying_fly
well this is awkward...
Yeah you could say that
there's a few ways that you can do this
but I doubt that they intended for you to just bash out the value of the expression explicitly
which is why I kinda like this
π π
it's kind of silly imo but π€·
you got plenty of time β€οΈ
like, why is there a 4 in part ii if it's just saying the ratio is nonnegative
what are you aiming to join next
yeah that too lol
it's giving the sat/jee just adding extra stuff for no reason
fr
π±
this be looking familiar
slayyy
dm solution too it looks intresting
π
ok
Guys
What are your opinions on khan academy vs aops books? I am currently reading introduction to algebra by aops, I really like it but some people prefer khan academy, what do you think?
why?
its coverage of the material is far too surface level
it's like if you wanted to sparknotes middle and high school math without any of the underlying rigor
- not enough exercises for a lot of the topics (especially for AP calc)
and their whole chatgpt enshittification
alright, that makes sense
aops books are great, but solving previous years competition problems and then learning what you dont know through other online resources is great too
but aops books are good for introduction
Yeah, I agree, that is what I am most focused on doing btw, but between these resources that you mentioned, I always liked aops books, there are tons of problems and some really nice explanations
What other online resources do you like?
Previous tests like amc, aime, usamo, bmo, tournament of towns, and others are good
youtube has many good courses that are useful and free
some previous olympiad medalists or coaches have websites
Indeed, organic chemistry channel has saved me a lot
yeah
the only one I know is evan chen's
this guy has a really great channel
Interesting, going to check his videos later
Are you studying for math olympiads either?
organic chemistry tutor is also far too surface level to actually help at all for contests
Anyone knows a good site to review limits?
yes
probably if you can find the stewart single variable calculus or precalc book online somewhere
Youβre studying for Olympiad math?
yes
Nice, howβs it going?
good
Elaborate.
I want information
On another personβs experience.
With Olympiad
I have been practicing previous years
and so far it's going well
Im able to solve much more problems than I used to be able to
especially with things like geometry which used to be by far my worst subject
Like how bad.
Hopefully you suceed.
ong fuck geometry
Indeed depending only on his channel might not help at all
the math youβd need to pass an intro level undergrad class or a typical high school class
neither are particularly deep or difficult
But like, his short videos can help a little with some introductions to new subjects and remember some other subjects
Usually when I forger something kinda easy, his videos helped me
but indeed, he doesn't show a lot of problems
Do you like any other sources besides these we already talked about?
the problem is not the quantity
it's the "quality"
he only covers the most basic trivial plug and chug examples
if you need it to pass your standard algebra 2 math test it's probably fine
if you need to do anything slightly more substantial
hell no
Indeed studying only with his channel isn't a good idea
What about u
is it just me or is aops website the slowest thing ever
I used to not be able to solve any competition geometry problems, not even amc level
π¬
I was in a similar situation.
is anyone here participating in ARML local this year? i have some clarification questions about the event
Hm
im in 8th grade and doing some comp math and soon one of my math classes will end
any suggestions for another math curriculum or class u would recco
i alr do aops
and some other classes
Guys i need help understanding this
i already know the answer
it's kangaroo math 2024
can u translate to english
yup that is correct but how did you get it knowing that they both have opposite directions and we dont even know the pace in which they make a turn, since its freely
I think it can be inferred that the hexagons are rigid and they don't swap positions randomly, so the distance from C to A is 2 counterclockwise, so you move F counterclockwise twice, and you get from F - E - D
yes sure
Two hexagons with the same center, one with letters and the other with numbers, can rotate freely around their center. In the figure, the letter F is next to 6. Which letter will be next to 1 when the F is next to 3?
you dont need to account for pace bcz the angles r same and 1 is 2 counterclockwise from 3
so just find what is 2 counterclockwise to F
1 is 2 counterclockwise?
directions of turns dont matter
mb 2 spots away from 3
because to move from 3 to 1 you need to rotate counterclockwise
yeah
Imagine a clock with only 6 hours
yes i get it
alr
but if they turn at the same time its not possible right
ok now i don't understand lmao
please translate it
lol
my french is horrible
use google translate
can u use it? like send it the pic and tell it to translate it for u
how? with pic?
i cant copy paste
its kangaroo
olympiad
i don't pay
oh then i'll try
ok
Six packages are placed on the platform of a truck. Manu unloads them to place them on the ground. He takes one package at a time and only if there isnβt another package on top of it. He places it either on the ground or stacks it on top of those already placed, and he wonβt move it again.
Which of these stackings could not be obtained by Manu?
hmm... lemme think
hell nah D is sus as hell
yay
wait only now i got it
i didnt know that the pic at the right was in the camion
lol
yea
he took em from here
wait you arent french right?
ok yea makes sense
im not
lmao
why
because neither of us were understanding the question at first instance
lol
no but i understand french really well
ohh
im on this question now
how do we calculate the perimiter
or idk how to spell it
peremiter
?
of the gray part
well first of all i think it says that the white parts are square
if i understood it correctly
yes
benjamin cut those white squares
2 3 6 and 1 cm
ok i see that its 36 cm perhaps
wait lemme see
yea but it's easily calculable
in the perimeter you have at least 3+3 (2 sides of the 3x3 square), 6+6 (2 sides of the 6x6 square), 1+1 (yea u understand it) and 2+2
yes
and then you have 10-3-2=5 on top, 10-3-6=1 on right, 10-6-1=3 bottom and 10-2-1=7 left
not times* 4?
no because 2 of the sides of the squares aren't in the perimeter
oh?
so you have 6+12+2+4+5+1+3+7 which gives you 36
niice
you do know that these are available en anglais
here I have another problem today:
why is this so familiar
for the ARML Local, are teams supposed to find the nearest school that is competing in or is every school team supposed to host the competition at their school?
if there is no nearby site then just get like a parent to host it
thats what happened in chicago at least\
yes but i have a practice olympiad today at school and its in french not english
Like im good in french dw, i speak and write french better than some of my teachers, and we study math, physics, biology in french
nothing to worry about
Ok guys they said 3 identical cubes are on a table, what is the sum of the 3 numbers written on the faces that we put on the table.
is it a b c d or e
A general method might be to find the opposite faces
That might be slow but works all the time
Which competition is it ??
13+22+8
by the second cube you see that beneath 8 is 13, by the third cube you see that beneath 13 is 22 and by the third cube you see that beneath 22 is 8
it's C
unfold the cubes, somewhat like this and check which numbers are adjacent and which are opposite. If you do it properly, you can solve the problem easily