#competition-math

1 messages · Page 38 of 1

ornate blade
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I was told that these problems were carefully designed to have elementary solutions (so that the Department could avoid scandals) that were nearly impossible to find. Any student who failed to answer could easily be rejected, so this system was an effective method of controlling admissions.

astral jacinth
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yeah

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oh i never checked yt

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i should

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ty

sharp sandal
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If anyone from India, are these online classes from Unacademy, PW, etc. enough for Jee Mains if you study well from your side? I have no experience of it so I am just thinking if online or offline classes will be better.

hexed thistle
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No too old

ornate blade
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pray that the 13 year old who replies to this won't drive you insane

scenic kestrel
stable umbra
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Does anyone have any tips for taking the Putnam exam other than learning the material more and practicing questions

willow bramble
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Does anyone know any free textbooks that could help me on the AMC10?

stuck tartan
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they were created to prevent jewish students from entering universities or mshtg

pale berry
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Last tuesday i experienced the unfairest experience i have ever had on olympiads, you see, i went to a very recognized school on my city to participate in olympiads , so, i go and get presented the next problem: On the sucession: 8,2,-4,-10... determine if 132 is part of the sucession. first thing i do is check if 132 is a 6 multiple , and turns out that it was, so i said yes and they said that was not the solution, so i try to do all the terms until 132, but no, the guy that was checking on the participants take my paper out of my hands and tells me that my solution needs to be checked by organizers, the thing is that i had 180 seconds to solve, by the time the paper was brought back to me i got 30 seconds and got to do until 112 and time finished. Note that this is supposed to be 10th grade (Colombian 9th grade) olympiads where i saw 8th grade problems. Opinions on this? What could i do to participate on TRUE experiences of olympiads?

astral jacinth
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Anyways, the succession is going the wrong way so even if it were 12, 6, 0, -6, 132 wouldn't show up iirc

pale berry
astral jacinth
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I've never really done a math Olympiad before but that sounds infuriating

pale berry
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yeah it was

torn bane
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Can anyone coach me on competitive math problems?

pallid tundra
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this is not the place to ask for that

torn bane
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It's the competition math channel, no?

ornate blade
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if you have a specific comp maths problem you would like help with, you can just post it here

torn bane
winged sluice
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What's 1÷0?

near hill
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That doesn't produce a result.

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Divisions with 0 in the denominator do not have a defined meaning.

torn bane
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does IMO or AMO have varying tests for different grades?

next coyote
near hill
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They didn't ask about a limit, though.

winged sluice
safe elk
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but no, IMO and AMO are the same for all grades

digital quiver
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cuz we have TH=TD

so then we can just prove TH.TI = TE.TF = TD^2 = TH^2

but stuck here

novel karma
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Bro why you sending ts here

prisma python
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i think it was a bot lol

novel karma
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lol

hardy basin
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I see this channel dedicated for competetion maths so can can anyone tell me resources from here I can prepare for Maths olympiad?

austere wedge
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i get the answer but like

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how in gods name do you come up with it

astral jacinth
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What is it

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The bottom equation is the first minus thrice the second plus thrice the third I think

austere wedge
stoic tinsel
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you can find the difference between 1st and 2nd equation

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then the same for 2nd and 3rd

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you get 3x + 5x + 7x + 9x + 11x + 13x + 15x and 5x + 7x + 9x + 11x + 13x + 15x + 17x

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the difference between them is 2x + 2x + 2x + 2x + 2x + 2x + 2x

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adding that to 3rd gives final equation

astral jacinth
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Also I hoped the three equations were linearly dependent and they were!

stuck tartan
# austere wedge

basically finite differences on the sequence n^2 if ur familiar with it

sleek helm
# austere wedge

You can row reduce the. Use the first 2 factors to determine the right linear combination

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Do L2 <- L2 - 4 L1

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L3 <- L3 - 9L1

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etc.

manic tulip
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My approach was trying to make 100 with plus or minus 49, 64 and 81. The other stuff just works out then.

digital quiver
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im out of idea for this problem ive been thinking it for like 2 days

near hill
prisma python
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yeah there was a scam that was deleted

worthy fable
# austere wedge

There are better ways of thinking but if can’t see it then can always do the algebra until it gets clearer

worthy fable
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or like this

azure hull
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hello ow can i train for the IMO ?

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im in 10th grade

pallid tundra
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to be blunt: if you need to ask that question you’re not ready to do IMO level problems

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start by learning about the qualification process from your country

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what contests do you need to do to enter the qualification process?

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study for those, do well enough to advance, repeat

autumn linden
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is this happening to everyone?

woeful orbit
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Hello

keen mirage
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hello

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are aops volumes 1 and 2 good for training competition math at a middle school level (like mathcounts, amc 8 and 10, MOAA, and other things like math kangaroo)?

pallid tundra
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they’re very outdated compared to modern resources, supplement with actual recent contest problems

pallid tundra
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I have no idea what that is

keen mirage
pallid tundra
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haven’t looked at middle school level stuff in at least 7 years

keen mirage
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mathdash is like a practice platform thing

pallid tundra
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don’t restrict yourself just to one platform

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as long as you’re practicing on challenging problems you’ll be improving your skills

keen mirage
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so

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yeah

stuck tartan
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there’s a decent amount of ai slop and the educative material is mid

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If you want to do the contests feel free to do them but there’s better options for an educational experience

thin geyser
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is there anyone who got a good score on the amc 10 or 12 who can help me study

minor yarrow
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guys

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how do you register amc 8

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and mathcount

keen mirage
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or for mathcounts

stoic tinsel
keen mirage
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oh

violet lark
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Can someone help me for Thailand IMO Heat round?

#

Secondary 1

rare sable
sleek ivy
thin geyser
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Umm last time I took it I got 76 ish

simple drift
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I HAVE BEEN BEATING MY HEAD AGAINST THE FUCKING WALL, AT THESE GOD DAMN MOTHERFUCKING ALCUMUS PROBLEMS FOR 2 GOD DAMN HOURS! IT MAKES NO FUCKING SENSE! ITS ALL SO FUCKING STUPID GOD DAMN IT! WHAT THE FUCK DO THESE STUPID FUCKING ASSHOLE BITCHES WANT ME TO DO!!!!!!!!!

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FUCKKKKKKKKKKKKKKKKKKKKKKKKKKKKKK

simple drift
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I’m so fucked bro

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It was casework counting

novel karma
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Bro chill the fuck out

pallid tundra
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secret achievement “ragequit”: leave alcumus for 12 hours after getting a problem wrong

simple drift
pallid tundra
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80 😭

simple blaze
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uhh can anyone tell me about incho ? ive heard about it before as im preparing for JEE but have no idea on what it actually is

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like whats the level of it

simple drift
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can u help

stuck tartan
stuck tartan
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DHR?

lavish marsh
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Are there any tricks, or not-well known formulas for conic sections that anybody can slide my way? Im doing an Oral presentation contest for the North Suburban Math League in illinois and our topic is Conic sections from AoPs Intermediate Algebra Chapter 5

soft vigil
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the most important part is solving problems and getting consistent (fewer sillies)

soft vigil
lavish marsh
soft vigil
stuck tartan
robust dune
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Js

fallen shale
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Can anybody help me with gmat exam..i haven't started anything and didn't touch math for 2 yr

fallen shale
#

Data Sufficiency

Data Analysis (graphs, charts, tables)

Multi-source reasoning

Two-part analysis (quant + verbal mix)

Statistics & probability applications
Arithmetic (percentages, ratios, fractions, averages, profit-loss, simple & compound interest, speed-distance-time, work-time, number properties, etc.)

Algebra (linear equations, quadratic equations, inequalities, functions)

Word problems

Geometry basics (lines, angles, triangles, circles, coordinate geometry)

Statistics basics (mean, median, mode, standard deviation, probability, permutations & combinations)

rare sable
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Of syllabus later to statistics

fallen shale
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Ok thanks ..can i ask doubt on personal chat?

viscid plover
thin geyser
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can someone help me prepare for aime

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i got a 76 on amc 10

dusty pulsar
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hello!

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so for the first time ever, I'm going onto my highschool's math team!!

novel karma
thin geyser
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wdym

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that is really bad

stuck tartan
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It id physically impossible to get a 76 💀

novel karma
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Bro give the actual score

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6 x correct + 0 incorrect + 1.5 x skip

thin geyser
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idk

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it was 76 ish

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i think

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might of been 76.5

glossy tinsel
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what do they mean by this what is it specifically

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are they referring to method of differences for summations?

green jetty
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Difference equations are like x_n+1 = x_n + a
Or something like x_n+1= x_n + ax_n
Or something similar
So basically it's a equation which relates one term of a sequence with another

glossy tinsel
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is that not just a recurrence relation

green jetty
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Yes

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But yeah , they will ask you solve such an equation

glossy tinsel
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ahh alright thank u

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im so confused as to why they chose to put it that way

green jetty
echo hatch
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esesd

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Hello.

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Can you hear me?

rare sable
echo hatch
#

NIce to meet you

rare sable
#

yep

echo hatch
#

I'm sorry interrupt you.

rare sable
#

?

echo hatch
#

I am a university student, and I came here first.

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can you help me?

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I don't know about here, well

rare sable
rare sable
echo hatch
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anything about here

rare sable
#

See there are channel here

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Where ppl post doubts

echo hatch
#

yep

rare sable
#

And some smartass ppl answer them

echo hatch
#

ya

rare sable
#

You can do discussions to

echo hatch
#

!

rare sable
#

Related to maths

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I guess u got it

echo hatch
#

in chill, what can I do?

#

hello?

rare sable
echo hatch
#

ppl? So sorry,What is it?

rare sable
#

People

echo hatch
#

oha. sorry.

rare sable
#

Bruhh.

echo hatch
#

hhh

#

and How can I call you?

rare sable
#

Got any doubts related to concepts in maths , question solving shoot!

rare sable
echo hatch
#

sorry

rare sable
#

Using @ sign

#

@rare sable

#

See easy

echo hatch
#

LOKI?

#

it is your name?

rare sable
#

Nickname

echo hatch
#

I see.

rare sable
#

Is happy smile ur name

rare sable
echo hatch
#

It's too my nickname.

rare sable
#

Really

#

Bruh

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I'll call u happy

#

Suits as a nickname atleast

echo hatch
#

Would you like to be friends?

#

hi?

#

LOKI?

#

?

rare sable
#

Ok

#

Happy

echo hatch
#

Where have you gone?

rare sable
#

Busy

echo hatch
#

why?

rare sable
#

organic chemistry

echo hatch
#

studying? now

rare sable
#

Yep

echo hatch
#

or testing

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lecture?

rare sable
#

Studying

echo hatch
#

Ok.

rare sable
#

Self study

echo hatch
#

Good

rare sable
#

Byee

echo hatch
#

👍

rare sable
echo hatch
#

When can I see you?

rare sable
rare sable
echo hatch
#

I don't know it

rare sable
echo hatch
#

right know,possible?

#

Hello?

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anybody here?

next swan
rare sable
radiant jasper
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Unfortunately I cant join the math competition in the college and im f-king upset AAAAAA

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Cuz i finished all math class

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But I have still 3 years of college left

simple drift
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I think I got the tech , to get ready in time. I have very little studying done but if I do 2 AoPS chapters a day 17 alcumus sections a day starting from the very start I have a full 17 days I can spend fully on doing real past AMC 10 problems and watching old videos reviewing full past exams

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Can I make it

feral drift
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olympiad people, help me solve this

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On line l, points A and B are placed, and on line S parallel to it, points C1, C2, ..., are placed in order. Find the total number of triangles formed inside the trapezoid by connecting these points in all possible ways.

feral drift
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yep no one figured it out

ivory ember
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cause it can lead to helpers double answering, which is inconsiderate of their time

feral drift
#

Got it

viscid plover
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Let's see who is able to solve this problem.

The price of a gem is proportional to the square of its weight. Prove that the maximum depreciation occurs if we split it in half.

tiny eagle
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One fraction of the gem is x so the other part is 1-x

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The price is proportional to (1-x)^2

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This is minimized when x=1/2 by parabola

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QED

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Olympiad level proof trust

stoic tinsel
stuck tartan
stoic tinsel
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Then, when connecting C points to B, it creates a new triangle, and extra ones for each intersection

stoic tinsel
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Trying smaller cases is probably the easiest way

manic tulip
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Has anyone here taken the octm and if so, what was the difficulty of the matrix probs on it

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Dont say answees obviously, i just want to know how much i should focus on them

honest pollen
#

does anyone wanna join my server?

manic tulip
#

Whats it abt

viscid plover
#

A hint, this is an optimization problem.

kind pulsar
viscid plover
#

The minimum price

kind pulsar
#

ohh

zinc escarp
viscid plover
#

But x is not equal to 0.5, don't put that equal, it's false. They put 0.5 so you can verify that value.

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And not even x = 0.5

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So, solve it well

near hill
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(Assuming, as we need to for the problem to make sense, that we're implicitly supposed to cut the gem into two pieces. If there can be more than two, the specified conclusion is not even true -- we can approach a depreciation of 100% by grinding the gem into dust...)

wintry kiln
#

I have about less than a month before like an invitational math contest, I have a bit of backgrounds working with comp math, should I just grind out the questions of past papers or is there something better to do

prisma python
#

<@&268886789983436800> spam bot

kind pulsar
# feral drift On line l, points A and B are placed, and on line S parallel to it, points C1, C...

Let number of points in line S = n

Case 1: Top vertex on line l
Number of triangles
= C(n,2) * 2
= n!/(2!(n-2)!) * 2
= n(n-1)/2 * 2
= n(n-1)
= n²-n

Case 2: Top vertex on line S
Number of triangles = n

Case 3: Intersecting lines
Fix the 2 points on line l
Pick 2 points on line S
Each results in 2 triangles
Number of triangles = C(n,2) * 2 = n²-n

Total number of triangles
= (n²-n) + n + (n²-n)
= 2n² - n
= n(2n - 1)

rare sable
#

number of ways of selecting 3 points out of 4

tight trench
#

which book is best for olympiad math?

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challanges and thrills of precollege mathematics 4th editon book and mathematical Circles Russian editon?

rugged saddle
#

how to sign up for amc 8

queen oriole
# tight trench which book is best for olympiad math?

Really depends on your level. Overall, I think no book is the best for all Olympiad math, but some are really good for certain topics. For example, the best geometry book will most likely not talk about ROUF, etc.. overall, start with aops, then go deeper into a certain subject

wanton mauve
fallen adder
#

you do not want to be in the southeast

scenic kestrel
#

otherwise if u live in a decently populated place there should be a local testing center

cosmic fractal
#

yo is the P(n) approximately 1/(4n *sqrt(3) *exp(pi (sqrt(2n/3))
real?

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I found it off the movie

cosmic current
cosmic current
tight trench
#

Thanks, as also this is not the channel for book discussion so maybe u understand!

agile gazelle
agile gazelle
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Can any1 help in this putnam question

scenic kestrel
#

if u cant find it ask local colleges and universities

heavy pagoda
# agile gazelle

very natural way to solve such problems is to set them up on complex plane let the center of the circle, $O$, be the origin of the complex plane, so $O$ corresponds to the complex number $0$. Let the vertex $A_1$ lie on the positive real axis. Since it is on the circle of radius $R$, its coordinate is the real number $R$.
The vertices $A_1, A_2, \dots, A_n$ form a regular $n$-gon inscribed in this circle then they can be represented by the $n$-th roots of $R^n$. The complex number corresponding to vertex $A_k$ is therefore given by:
$$ a_k = R e^{i \frac{2\pi (k-1)}{n}} \quad \text{for } k = 1, 2, \dots, n $$
These $n$ values are precisely the roots of the polynomial equation $z^n - R^n = 0$.
The point $P$ lies on the line segment $OA_1$ extended beyond $A_1$. Since $O$ is the origin and $A_1$ is at $R$ on the real axis, $P$ must also lie on the positive real axis. Let its coordinate be the real number $p$. The condition "extended beyond $A_1$" means that the distance $OP$ is greater than the distance $OA_1$. Thus, we have $p > R$. the distance $OP$ is simply $|p| = p$

gilded haloBOT
#

Yuxuan Wang (Trusted By Mods ®)

#

Yuxuan Wang (Trusted By Mods ®)

heavy pagoda
#

recognizing the product might be helpful here $\prod_{k=1}^{n} (p - a_k)$. since the complex numbers $a_1, a_2, \dots, an$ are the roots of the polynomial $z^n - R^n$, we can express this polynomial in its factored form:
$$ z^n - R^n = \prod{k=1}^{n} (z - ak) $$
This identity holds for any complex number $z$. maybe then we can therefore evaluate it at our specific point $z=p$:
$$ p^n - R^n = \prod{k=1}^{n} (p - a_k) $$ this much takes u very far in proving final thing u can move from here easily ig

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many putnam problems r often repetitive in structure or ideas i have seen such problems like lot of times

dusty pulsar
#

I'm going into my highschool's math team!

pallid tundra
#

nice

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when is y’all’s first competition

novel karma
#

What’s a fast way to solve 2011^2011

pallid tundra
#
  1. don’t
novel karma
#

Im mostly trying to look for patterns but nothing seems to work

pallid tundra
#

what are you looking for

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its actual value?

novel karma
#

Oh sorry

pallid tundra
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its value mod some number?

novel karma
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I meant hundreds digit lol

pallid tundra
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oh these kinds of problems bleak

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uh

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take it mod 1000 and see how the digits cycle?

novel karma
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Yes

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I did that but i see no patterns

pallid tundra
#

you could reduce the exponent a fair bit with Euler totient

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and use similar tricks to try to reduce it to smth you can compute relatively easily

novel karma
#

Alr I’ll try again.

crisp mica
#

Hey guys, im a junior oding amc 12, and I took the amc 12 a 2025 just now and got 64.5. Is it possible for me to qualify for aime with one moneth left

pallid tundra
#
  1. spelling
  2. if you’re that far off cutoff when mocking it’s highly unlikely
stuck tartan
#

using fact that 11^phi(1000) = 1 (mod 1000)

faint thorn
#

guys im cooked for SMC could someone pls help me

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like helping me through past paper question and particularly logic

novel karma
stuck tartan
stuck tartan
ornate blade
novel karma
#

I didn’t even know what that was lol 😭

ornate blade
#

(10 + 1)^2011 = 1 + 10 * 2011 + 100 * 2011 * 2010/2 + 1000 * ....
= 1 + 10 * 11 + 100 * (units digit 5)
(mod 1000)

novel karma
#

But yeah binomial theorem is the best way right

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Like there are no cycles

ornate blade
ornate blade
#

consider that there are 3 terms before you get multiplication by 10^3, 10^4 and so on

novel karma
#

That’s smart

ornate blade
#

yeah it is just the binomial theorem

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of course there's some level of depth needed to answer it

novel karma
#

Lowkey binomial theorem is way better instead of finding patterns

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Like hundreds or thousands digit

ornate blade
#

there's also Hensel's lifting lemma that can be used for other problems where 1000 etc is also composite

reef condor
stuck tartan
unborn heart
#

I dont understand when is a fraction

near hill
#

The fractions are just certain numbers between 0 and 1.

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Those particular numbers have the nice property that the other trigonometric functions of the same angle will also be nice tidy rational numbers (which you can compute).

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That way you'll have everything you need for plugging into the angle addition formulas.

robust edge
#

Yall what resources should I use to study this syllabus. The document recommends Art of Problem Solving, Volume 1, 7th ed and Problem-Solving Strategies by Arthur Engel. Any suggestions?

heavy pagoda
#

i highly recommend it

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great book

robust edge
#

Oh ok Ill try it

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thanks for your recommendation

heavy pagoda
#

for example pham kim hung has great book on algebraic inequalities

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titu andrescu has great book on combinatorics

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and justin steevens for introductory number theory etc etc

robust edge
#

Ok I'll read them

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I was really confused for where to get questions from

sleek ivy
robust edge
#

Harvard undergraduate science olympiad India

lusty plinth
#

did anyone do usamts this round? it ended yesterday

queen oriole
#

Yes

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Not able to talk about it tho because of the extension

deep needle
#

and @odd talon

odd talon
#

i love usamts

deep needle
#

or tomorrow

proud dove
eternal arrow
#

cause i learned about it a few days ago

eternal arrow
radiant jasper
#

a + b = 10
ab = -11d
c+d = 10a
cd = -11b

Integrate (a+b+c+d) dx when a,b,c,d ≠ 0 and are not equal also.

[No ai Allowed, just try]

deep turret
acoustic jetty
stray pumice
#

hi!

#

I'm new to competitive math and i want to prepare for an entrance exam but I'm having a lot of trouble writing proofs... basically i'm am idiot pls help T-T

novel karma
#

wlog is used in this problem but i don't get why/how it works

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like setting a = 1

manic heron
#

anyone done the UKMT SMC ?

orchid latch
#

yes

manic heron
#

how wasit

orchid latch
#

it was okyay

ivory ember
# novel karma like setting a = 1

In the future, you should give all the context when asking your question (so in this case, that would involve actually showing the solution where it says "WLOG").

Anyway, I looked it up, so don't worry about it this time. The use of "without loss of generality" is abusive - they're moreso abusing uniqueness (using the fact that there must be a unique answer as per the question format, so they're picking a simpler case to work with). This is supported by the solution saying later on that "this time-saving trick works only because ... a^2 - b^2 + c^2 will always be a constant" - unless you proved that a^2 - b^2 + c^2 must be constant beforehand, you cannot say a = 1 without loss of generality.

jaunty ginkgo
jaunty ginkgo
novel karma
#

I only use it in geometry problems

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Where sides aren’t given

near hill
#

There's nothing wrong with saying "without loss of generality" when it's actually clear that no generality is lost.
The problem is more that there doesn't seem to be any reason (other than metagaming) to expect that picking a value for a won't lose generality.

#

It's fairly bad form to pose a problem that gets so much easier by metagaming it (or, conversely, so much harder if you're purist and refuse to look at the answer options).

novel karma
#

What’s meta gaming?

near hill
#

In this context, arguments that attempt to derive information from the fact that the question was asked at all.

#

It's not really a crisp technical term.

#

However, when we're done being disappointed with the problem setter, it's actually an interesting problem. The two linear equations we're given pick out a straight line in (a,b,c)-space, and it's really extraordinary that the quadratic expression a²-b²+c² would be constant along a line -- that's not something one would expect in the general case.
The solutions to a²-b²+c³ = D when D is a positive constant is a one-sheeted hyperbolid, one of the classical example of ruled surfaces.

jaunty ginkgo
near hill
#

That's where the problem is less than satisfying.

jaunty ginkgo
#

Are we doing algebra?

near hill
#

Well, I mean, ignoring the line, whenever you pick a D>0 and look at the equation x²-y²+z²=D, that gives you a one-sheeted hyperboloid.

#

But for proving that the line in the problem lines in one of those hyperboloids ... the algebra-bashing way would be to find a parametric equation for the line and plug that into a²-b²+c², then simplify and see that it becomes a constant after the dust settles. That's sounds rather cumbersome.

#

If you already know you're going to find a constant, it would suffice to find three distinct (but otherwise arbitrary) points on the line, evaluate a²-b²+c² at each of them and then see that those three values are equal. Then note that the only way a quadratic expression can have the same value at three different points on a line is if it is actually constant along the line.

jaunty ginkgo
#

fern_silly math is weird

high goblet
ornate blade
#

how are you?

high goblet
#

btw when the embargo's over u'll probs find more discussion of SMC in the UK section of mods

high goblet
ornate blade
#

wait this isn't hlounge

high goblet
radiant jasper
#

Year or two ago

#

Making circuits

white pier
#

well @high goblet are you born on 27 ?

radiant jasper
pallid tundra
faint thorn
#

Hi guys

#

Did anyone do the SMC

#

On Friday

pliant swallow
novel karma
#

What do yall think about mathdash

#

Better than alcumus or nah

faint thorn
#

I’m a 15yr old doinf it

#

I only managed to do 21 of the questions

remote island
#

tbh, i use mathdash more often and just skim through alcumus problems

pliant swallow
#

so i dont know whether all my answers saved

#

😭😭😭😭😭

pliant swallow
pliant swallow
#

all my orher school friend only did like 15+

#

it was really hard ngl

austere wedge
#

Is there any list of like

#

recommended exercises for aops books

#

why do they have. So much.

stoic tinsel
#

Honestly js grind it out

#

It’s long but worth it

#

If u master everything in it ur set for a lot of comps

manic heron
#

Guys

#

How was the ukmt smc 2025

#

I just marked my paper

#

Do you think the grade boundaries for bmo will drop

#

Like prob 104???

amber blade
#

does anyone know how to answer this imocsea question

lunar badge
#

then you can just take the area of each quarter circle and add them, subtracting ABE, and then subtract all that from the square to get DEC

kind pulsar
jaunty ginkgo
pallid tundra
#

eh i dont think this would be unreasonable for a strong 5th grader

amber blade
modern tartan
#

hlo

ornate blade
#

they already have these

#

the whole paper is lower secondary difficulty: these concepts are usually taught in 8th or 9th grade

#

but if kids go to competition maths tutoring, they learn them earlier

jaunty ginkgo
#

That's scary

ornate blade
#

I'm not saying these are hard, but most people don't know how to do these in 5th grade

#

just like most people can't do AMC8 problems in 5th grade

near hill
frigid sable
#

Are there books based on such problems?

ornate blade
frigid sable
#

@ornate blade do you know where I can find such problem sets for competition math?

#

Sub tenth grade level

quick verge
#

what are AMC

ornate blade
#

also if you register an account on AoPS you can get Alcumus problems

jaunty ginkgo
#

catno scary in anyway

quick verge
jaunty ginkgo
#

My 5th grade cousin asked about telescope sum once but it's in term of product not different of square like this bruh

amber blade
ornate blade
#

just cause the teacher is teaching at a million miles per hour doesn't mean the students are following

jaunty ginkgo
ornate blade
#

also like contest maths is different from regular school maths

#

regular school maths is definitely not this advanced

frigid sable
#

I wish to do it

#

I find it hard to do it through pure willpower alone

amber blade
#

7:30am to 7:30pm

jaunty ginkgo
#

But that's still kinda crazy

ornate blade
#

cause if the school buses left any later, we'd spend way more time in traffic

amber blade
#

Tbh i dont even think im gonna pass imocsea 😭😭 goodbye japan trip

quick verge
delicate meadow
#

When do we register for AMC this year?

#

I heard the deadline is on 14th

wraith lagoon
#

any volunteers?

high goblet
#

i mean if it didn't save in the end and you think doing bmo1 would be beneficial you could always pay for a discretionary

high goblet
ivory ember
# wraith lagoon any volunteers?

In the future, please show what you’ve done so far when asking for help - it gives us more context of where to help you (and saves our time from explaining things unnecessarily). \ \

By definition, we have
$$I=(A^{-1}+B^{-1})(A+B).$$

Now, consider expanding this.

gilded haloBOT
#

Civil Service Pigeon

ivory ember
#

Further hint: ||Multiply this by A.|| On the same thread, ||multiply by B as well.||

wraith lagoon
#

i just was wondering how someone else would solve it

shy raptor
near hill
ivory ember
gilded haloBOT
#

Civil Service Pigeon

near hill
#

How did I miss that?

forest grail
near hill
#

First, "right triangle where the square of the length of the hypotenuse is 4 times the area of the triangle" lets you conclude something very specific about the angles/lengths in the triangle.

forest grail
#

bro can someoen helptho!

near hill
#

Fairly sure I'm not your brother, but I did post a hint.

novel karma
#

anyone else having this problem

#

i can't seem to get the aops website to show

iron terrace
#

is studying 1-2 hours a day enough to prepare me for my mathcounts chapter competition (in late feb)

#

if i qualify for state, i would prob start studying 3-4 hours

heavy pagoda
#

cool

stuck tartan
#

what can you conclude about a and b

kind pulsar
# forest grail help

Let length of the 2 legs be a and b and length of hypotenuse be c
using Pythagoras we get:

a² + b² = c²
c² = a² + b²

Area = ½ab

therefore:

c² = 4 * ½ab
c² = 2ab
a² + b² = 2ab
a² + b² - 2ab = 0
(a - b)² = 0
a - b = 0
a = b

thus the right triangle is an isosceles right triangle
since it's a right triangle the circumcenter lies on the midpoint of the hypotenuse (Circle Theorem)
and one of it's angle bisector is also the height which connects the point of the righr angle to the circumcenter
thus it also bisects the hypotenuse since it's isosceles

#

hence option (A)

chilly sluice
#

hey can someone help me out here, i keep getting 9216 on this after a few tries but my answer sheet says 9210

formal ice
#

does anypne know what happened to aops? i literally can't find any webpages that are actually helpful

#

i wonder if it's my disable google ai extension?

#

or did its seo get fucked majorly

pallid tundra
#

everything's still on their website

jaunty ginkgo
# chilly sluice

Ehhhh it's because: when one of the boxes is empty
Take 1 way in case one for example:
B1 B2 B3
Now let's say B1 and B2 are supposed to have even numbered balls but B1 is empty
And take one way in case 2 :
B1 B2 B3
Let's say B1 and B3 are supposed to have odd numbered balls but B1 is empty

#

Even though the assumption for 2 case are different

#

It's basically the same, as B1 have no ball , B2 has all the even-numbered ball and B3 has all the odd nunbered balls

#

There are, I guess,6 cases like this

chilly sluice
#

I guess they mean that a box with zero isnt odd or even

#

Thank u mane

#

Wait it says a box can be empty

chilly sluice
#

Since its 11 odd 10 even

jaunty ginkgo
#

oh wait

#

yeah lol

plush mist
#

вфьт

kind pulsar
#

so you need to subract them then re-add the number of cases where 1 box is empty

#

in each of case 1 and case 2 there are 6 cases where there is 1 empty box

#

so total 6×2 = 12 cases

#

9216 - 12 = 9204

#

and there are an overall total of 6 cases where there's 1 empty box

#

so 9204 + 6 = 9210

#

thus the reason you get more than you should it's cuz you counted the cases where there's 1 empty box twice since they are the same case in case 1 and case 2

rare sable
# chilly sluice

Take cases where you place all odd numbered balls only(11 balls) , even balls (10 balls) only, 1 box odd and 2 even and finally 2 even 1 odd

#

Use formula (n+r-1)^ C (r-1)

#

n is the number of Balls to be distributed

#

And r is 3 (to be distributed among)

#

And -1 is for empty boxes allowed

#

Hope this hint helps you

jaunty ginkgo
#

why y'all still doing that problem it's already be resolved

prisma python
#

i'm joining that olympiad too

hollow lance
#

i have been attempting olympiads for past 3 years

old sorrel
#

Hey so I am taking amc 10 and 12 and I was wondering if any of yall know a comprehensive study guide over the topics covered since I'm having some difficulty finding good pages on the web

pallid tundra
#

make one yourself

sleek ivy
thick gale
jaunty ginkgo
#

,w binom(23,2)

jaunty ginkgo
rare sable
#

Dude

rare sable
#

Their solutions may be easier than yours

jaunty ginkgo
#

cat_happycry I gave no solution

#

They ask why their sol is wrong

#

And I answer

rare sable
#

I js mean let others answer if they want too!

jaunty ginkgo
#

You are not supposed to give out the sol here

rare sable
#

i know

jaunty ginkgo
rare sable
#

but things ain't always according to Book

rocky kraken
#

hi guys

agile gazelle
#

Calculate |Z|^2

#

Its extremely hard compared to olympiad questions but its not a reason to not try

ivory ember
#

$\begin{cases} n, & n \text{ odd} \ 2n, & n \equiv 0 \pmod{4} \ 0, & n \equiv 2 \pmod{4} \end{cases}$?

gilded haloBOT
#

Civil Service Pigeon

ivory ember
#

$$|Z|^2=\sum^{n-1}{k=0} \sum^{n-1}{j=0} \omega^{k^2-j^2}=\sum^{n-1}{k=0} \sum^{n-1}{j=0} \omega^{(k-j)(k+j)}$$
Now let $m=k-j \pmod{n}$. So,
$$|Z|^2=\sum^{n-1}{m=0} \omega^{m^2} \sum^{n-1}{j=0} \omega^{2mj}$$
and the rest should be trivial if I'm not an idiot

gilded haloBOT
#

Civil Service Pigeon

ivory ember
#

i rlly need to sleep

agile gazelle
jaunty ginkgo
#

I have this pretty interesting problem that I haven't been able to fully solve

#

Using 12 iron bars to create the frame of a rectangular box with dimensions 20, 30, and 60. When placed outdoors, the edges of the box cast shadows on a flat surface. Assume that all the light rays are parallel. Determine the minimum and maximum values for the total length of the shadows of the edges

#

This's the whole problem, if you're curious. It doesn't state how the box is placed

uneven obsidian
jaunty ginkgo
uneven obsidian
#

well, we discussed it ourselves already

#

he doesnt know

#

i mean he showed me the question so

jaunty ginkgo
#

irealshit damn, must be tuff

uneven obsidian
#

yesh

sweet pewter
# uneven obsidian

||Let AE intersect BC at G. Easy to see that GF^2 = GD^2 = GB.GC. Let H lie on line BC so that G is the midpoint of HD. We get C, B, D, H as a harmonic set of points and F lies on (HD) -> F lies on an Apollonius circle||

uneven obsidian
#

hm

rare sable
dim gulch
#

HALO

#

I AM NEW GNG

pseudo venture
ivory ember
# pseudo venture

In the future, please show what you’ve done so far when asking for help - it gives us more context of where to help you (and saves our time from explaining things unnecessarily). \ \

I'd do this by counting the complement. There are three cases to consider:
\begin{itemize}
\item All $6$ digits are the same.
\item One digit appears $5$ times and a different digit appears once
\item All the digits are distinct
\end{itemize}

gilded haloBOT
#

Civil Service Pigeon

pseudo venture
formal ice
#

when i search amc12 i literally cant find aops unless i specifically google forit

keen lake
chrome ivy
#

anyone got some grade 11 question for competitions and could help out with them?

chrome ivy
#

math

jaunty ginkgo
#

I meant which math comp

chrome ivy
#

like my city's

#

grade 11-12

#

well technically 9-12

jaunty ginkgo
#

Well then I don't have any of those I don't know what your city is

chrome ivy
#

since every time its different problems

#

Ive found some that could be there

#

do i send it here or message you?

jaunty ginkgo
#

It would be better for one who knows or even have participated in that comp coaching

chrome ivy
#

Ive been there for 4 years so far

#

I found some similar ones if you could help

jaunty ginkgo
#

emojigg_Huh no, I don't think I can. I'm senior highschool

deep needle
#

Usamts delay 💔

#

Was supposed to drop yesterday

gleaming crater
#

$What fraction is to the n^{th} power?$

gilded haloBOT
#

Average_X^2

radiant jasper
late flint
#

is anyone here doing the carnegie mellon winter math comp?

sonic bridge
#

IS ANYONE DOING JEE MAINS OR JEE ADVANCED OR CMI OR ISI

jaunty ginkgo
#

Not me but JEE takers here are numerous

#

Well not that many but we do have

#

I also know some

sonic bridge
jaunty ginkgo
#

with what

#

a problem?

sonic bridge
jaunty ginkgo
#

just send it here lol

sonic bridge
#

OK

sonic bridge
jaunty ginkgo
midnight valley
deep needle
heavy pagoda
#

competition math channel is so weird lol

uneven obsidian
modern tartan
#

OLYMPIADS BE LIKE

rare sable
heavy pagoda
#

cuz i cant see any discussion which is remotely related competiton maths (talking about IMO/putnam etc)

#

i see homework problems mostly but nvm

rare sable
jaunty ginkgo
#

They're in their 24 hours study session

vapid crest
heavy pagoda
#

what tf do u even mean by that lol

#

also i have done fair bit of math olympiads those exams doesnt mean u have no life lol

jaunty ginkgo
#

KEK I just meant that they spent so much time grinding

heavy pagoda
#

u dont "grind" all day

#

also anyways this server has many working mathematicians who have fairly more work to do in that sense then but i think just quality of this channel is poor thats it

jaunty ginkgo
heavy pagoda
#

there r advanced channels below

jaunty ginkgo
#

Ngl I had like 6 hours back when I was studying for comp...

#

6 hours hw

#

For a day

#

After that I say no more for competition emojigg_Huh

hollow narwhal
#

just send it here lol

pallid tundra
#

this is not r/mathmemes keep your unfunny completely inaccurate generalizations of olympiads out of this channel

high goblet
#

(linked in channel description)

#

so mostly the ppl here will be those new

silk citrus
#

any good resources for combinatorics for math olympiads for begginers like for coloring invars monovars and stuff with problems

odd talon
#

who else eagerly waiting for usamts round 2

snow elm
#

Any suggestions for preparing CSMC?

abstract bolt
#

how hard is amc10 and amc12 compared to like calculus 1

abstract bolt
#

is it like sat

strange hemlock
#

Guys

#

Can I get a good stradegy for AMC 10

strange hemlock
fierce bluff
#

does anyone have suggestions for mathcounts? its my last year and i need to lock in on chapter sprint rounds i average 21/30 in 40 mins but thats not good enough for my schools team. i practice with rounds from 2019 and everything but i always struggle around the same point

#

i think im supposed to ask that here

strange hemlock
#

For the books try AMC 8 and MATHCOUNTS Level

#

There may be harder level problems but getting those right just means your even more prepared

strange hemlock
#

No problem

gritty eagle
#

Hi I’m in 6th grade can u help with this math counts question The second round of the Major League Baseball play-offs is “best out of 5,” meaning that two teams will
play each other until one team wins three games. How many different ways could this play-off match-up

#

This is an AOPS question for my homework

stoic tinsel
#

They either play 3, 4, or 5 games

fierce bluff
gritty eagle
#

Oh it’s for my robotics team

#

Thx for helping me also

hollow narwhal
#

That if you would say 2×4 and 2+4 are the same

thick gale
#

Wrong

#

It's 8 and 6

ornate blade
#

it's already a nebulous concept for a lot of adults

vapid crest
azure torrent
#

Is anyone here preparing for IMC( international mathematics competition) undergraduate or you know someone ?

jaunty ginkgo
#

uhhhh this channel is in category "pre-university"

#

so probably not

fierce bluff
#

just making sure hes aware dam

vapid crest
fierce bluff
#

“just making sure hes aware”

#

whats your problem

radiant shoal
#

how does comp math even work

near hill
#

What do you mean? Are you asking how competitions happen practically?

near hill
#

It varies from competition to competition, but a typical format will work more or less like a written exam, since competitions tend to be organized by or in collaboration with school systems. The problem sets are designed to be so challenging that even very good participants will not have time to answer everything perfectly; this makes it possible to speak about who did best.

delicate mesa
#

hi i have a competition this afternoon, its 5 am rn lol

#

do u guys have any study guides on the theorems?

#

especially binomial theorem and stewarts theorem because i genuinely dont know

#

oh also chinese remainder theorem i need to study theorems

near hill
#

If you haven't slept already, doing that will help you more than any amount of last-minute studying will.

queen oriole
delicate mesa
#

and im cooked for my exam thats why i woke up early

delicate mesa
#

is that stewarts?

queen oriole
#

Yeah

whole jay
#

Does you Binomial Expansion part include Combinations and Binomial Probability?

#

I don't know the context of your competition, but studying Pascal's triangle and the general expansion form of the Binomial is a good way to do it

hollow narwhal
#

Wrong

pallid tundra
#

pascal's triangle is like day 1 example to introduce binomial coeffs opencry

agile gazelle
#

You can visualize every theorem with pascal’s triangle

pallid tundra
silk citrus
hollow minnow
#

hey im preparing for a math competetion next month its called georhr mhor and how would i study for a competetion its largely focused on geometric knowledge and combinatorics and some trigonemetry but mostly angles but i could use some help

waxen frigate
kind plinth
#

im trying to do the amc 12

pliant swallow
#

heard the competition is soon

agile gazelle
winged quail
#

Got a problem at some idk what paper

Let F be a field and let f(x) = F[x] be
an irreducible polynomial of degree n.
Consider the field extension
K = F[x]/(f(x)).
Let a Є K be the image of x under the
canonical projection. Prove that:

  1. K≈ F(a), the field generated by a
    over F.
  2. Every element of K can be uniquely
    expressed as a linear combination
    ao + a₁α + . . . + an-10-1, where
    ai Є F.
  3. If f(x) is separable, then K is a
    separable extension of F.
pallid tundra
soft vigil
soft vigil
#

you can let the LHS be a second degree polynomial

#

cause x_1, x_2, etc are just coefficients of some terms of it

#

then you can set whatever

#

and its like f(1)=1, f(2)=12, f(3)=123 and you can find f, then answer is f(4)

reef condor
stuck tartan
civic trellis
#

@soft vigil

#

check dms

#

nvm u have to add me first

soft vigil
hollow minnow
#

anybody got advice on youre first math competetion

subtle sundial
#

prepare months in advance

#

dont learn new topics the day before

#

just review if possible

novel karma
#

Don’t mean to be racist

pale berry
gaunt egret
jagged violet
#

You could use resources like amctrivial, aops, etc for problem sets to do

rancid stratus
#

i wrote the question in the top left where it says log2(x^2) + 2logx(8) = 392 / [log2(x^3) + 20logx(32)] given x > 0, can someone verify if i got my a-substitution calculations right

ivory ember
gilded haloBOT
#

Civil Service Pigeon

rancid stratus
#

oh ok thanks really needed that

subtle sundial
#

its the nerves that get you during your first competition

steel parcel
#

I am not sure, however.

#

Hello, everyone!
What are some book recommendations for AMC10? I aim to make USAJMO this year but have my 8th grade (next year), my 9th grade, and my 10th grade years.
I use all books on the AOPS Book Store, handouts, AMC books, formula books, and other resources found on https://mathematics.gg/books.

worldly swift
low wind
#

Is there anyone here that went to community college and participated in AMATYC?

tired cobalt
#

Everything in here lowk making me tweak

#

Do they cover this stuff in a levels

#

I thought this was meant to be pre uni 😭😭

karmic copper
tired cobalt
#

I even tried learning some of the content myself

#

To get ahead

#

And come here just to be humbled

rare sable
tired cobalt
#

The maths got me confused bro

#

But I thought it was meant to be pre uni

karmic copper
#

i think this is the higher end of high school

#

so just before uni

#

or collage

random rain
#

um so im in 10th rn, im in imo rn, what other stuff shoulld i enroll for??

#

like maths related

#

or anything else

#

i signed up for imo il be writing it in like a couple weeks

random rain
#

my extracurriculars are kinda ded

quick haven
#

chat

#

anyone here participated or will participate in International Youth Math Challenge?

quick haven
prisma python
#

depends on where you live and what olympiads are available, but there should be at least a few

steady elbow
#

Should I study for the Putnam exam while in high school?

#

Does it help my academic journey in college?

#

I really need an advice on this, I find the material in the exam interesting. Also I'm doing well in my senior year and I want to try smth out. Is putnam worth trying?

random rain
#

here qualifying for the national olympiad tea,'s a big deal

#

i cant find anywhere to continue coursework tho

#

like the required coursework for the prep

#

like combinatorics which is extremely out of portion to the stuff we learn in school

half arrow
half arrow
quick haven
#

like is it a waste of time

half arrow
# quick haven umm why not worth it ? so the whole competition is not necessary?

In my opinion, yes. It’s not necessary because I don’t think it is that prestigious. You can do it just for fun and get a certificate, I don’t think 10 quid for a certificate is a bad trade at all. I didn’t do it because I knew I’d get stressed about doing well on the final round and divert my attention away from things that I actually wanted to do

pallid tundra
#

the MIT kids who dominate every time are coasting off their very strong HS Olympiad preparation

#

and you’ll be busy with more important things during your undergrad anyway

snow elm
#

how to do it

gilded haloBOT
#

Poly(^///^)

steady elbow
#

||you can brute force this, 7^2 aren't that many combinations||

orchid raptor
#

Guys how many hours do u study for math competition per day/week?

#

I know it depends on the type of competition and many other factors, but in general?

robust dune
#

From what I remember

orchid raptor
#

Which competition were u preparing for?

robust dune
#

I don’t remember

#

It’s been like 8 years since I attended it

random rain
stuck tartan
junior mason
#

And got selected in team?or is it some private olympiad

#

It must be some private olympiad
Because to get selected in imo team u need to clear many stages and only 6 students from a country are selected

random rain
#

no i mean the school titles it as imo

#

i mean ur really just writing lke prep for the exam

#

qualifiers essentially

random rain
#

ik

#

i rly dk y its titled as such

#

but that the name given to the exam

#

and ill write it soon

#

for th imo team i undertsand u have to write rmo

#

and a bunch other stuff

#

im rly not good enoughf or that stuff

#

soo if any of u have written the rmo in india

#

i was wondering if u guys had any tips for prep

#

balancing it with other prep like JEE stuff and what not

junior mason
#

This year i gave ioqm
Wont appear for rmo because im preparing for inpho and jee

#

My score was 48

random rain
#

is that good ?

#

mb i rly dont know

random rain
#

ill prolly write it after i finish boards

junior mason
#

Paper is tough

random rain
#

ic

#

what abt the syallbus

#

im too lazy to search it

#

send pwease

#

i genuinely have no idea of any kind of math outside 10th syllabus, but i've always wanted to learn

#

seems rly fun

#

is it ?

random rain
junior mason
#

Cbse

#

10th i did with icse

random rain
#

ic

#

im in icse rn

#

10th

#

maths marks aint that bad

junior mason
#

In icse only history and geography is dangerous

random rain
#

oh i got fried inhista nd geo

#

*in hist

#

mid term

#

i rly dont wanna talk abt my marks rn

#

🙁

junior mason
#

R u in any foundation program?like i was also styding 11th with 10th

random rain
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wdym

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no

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ill start next yr in cbse

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allenor base

junior mason
#

Next year give the olynpiad of the subject in which u have interest

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Like maths ioqm
Or physics

random rain
#

ic

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k ill keep that in mind

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ill focus on boards this yr

junior mason
random rain
#

ic

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portion is complete

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soo well see

terse canyon
#

yo

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has anybody here done the UKMT maths challenge

foggy python
#

take a look at this beautiful question

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this one too

ornate blade
foggy python
#

no

ornate blade
#

interesting

foggy python
#

its a fraction

ornate blade
# foggy python its a fraction

ah, I made a mistake when considering the polynomial ||(sqrt(x^2 - 1)^20 + 1)^2 - (7 sqrt(x^2 - 1)^3)^2 = 0||, so yeah, I see how it's ||187/53|| now

ornate blade
#

as for the first question, I have zero idea

foggy python
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this was in IOQM

ornate blade
#

I'm actually surprised you understood my method based only on that

foggy python
#

when i see a question thats interesting

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i try to see all the approaches to solve it

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so yeah

foggy python
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oh wait

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cyclic expressions maybe

foggy python
#

I solved it

odd imp
foggy python
dusty fable
#

anyone else qualify for BMO1?

outer raven
#

anyone else is argentinian and qualify for OMA national olimpics?

stuck tartan
#

1/2(1/r+i + 1/r-i)

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And then use a polynomial root transfer to create polynomial with roots r+i

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And another poly with roots r-I

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And then viettas

outer raven
#

anyone speaks spanish?

patent kernel
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ioqm is the qualifier

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and no that problem is not from IOQM

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It's from a random jee channel called "JEE SIMPLIFIED SUBJECT"

outer raven
#

like, IOQM is just a qualifier instance

patent kernel
outer raven
patent kernel
#

and if you qualify regionals you go to nationals

patent kernel
#

where

outer raven
patent kernel
#

then you can ask questions

outer raven
patent kernel