Відео

we want more videos keep up🙂😄😄😄😄😄😄😄

I am interested in math olympiad. It would be of great help if you make vidios for the very beginners me,who have never attempted non -routine mathematics but very interested and passionate about it. Book recommendations and study plans are things we need proper guidance about,but can hardly find a good mentor.

With P(-x, y) we can proof that f(x) = f(-x) or -f(-x). With P(0, -y) we observe that for y != 0 f(y) can not be equal to f(-y), so f(x) = -f(x) and so f(0) = 0.

How can I raise my level within two weeks?

Hey there.I would really appreciate it if you make a vide about bashing geometry with complex numbers. You know as a algebra-nt person its easier to work on equations and numericals.Thank you Shef.

thaaanks dear

I feel so inspired. Thank you for this amazing video! :)

I showed this to my friend who has never done competition math before, and he saw the trick immediately :o

ur from serbia?

From Morocco unfortunately you took a long vain detour...please be more strathward

Cant we just use the following logic: There isn't any function With standard operations that satify mapping primes to primes other than f(p) = p itself....

Extremely tedious ngl

I did this like, Wlog 0<a<=b<=c so a^2<=bc thus 1/a^2>=1/bc Similarly, doing for b and c we get, 1/a²+1/b²+1/c²>= 1/ab + 1/ bc + 1/ ac = (a+b+c)/abc Hence shown.

This problem ended up being kinda funny because I mistook the the i<j for I=<j and ended up solving (almost, there were 3 cases, and I took care of 2,5 of them, you could say) a harder version of the problem... I eventually concluded there was something wrong here and that an IMO P1 shouldn't be this difficult, read the problem statement again, realized my mistake, and ended up having a solution in 15-ish minutes thanks to the facts I'd already deduced while solving the harder problem. Well, that was fun, I guess.

Found it very useful while solving the question bank at AoPS. Subscribed and Liked!

You from Switzerland?

I had a different method. I took BC,AC and AD to variables say a,b and x then I applied appolonius theorem on Triangle ABD to get AB then I took Ang BAE to be theta and applied cosine rule one ABE and ABC to get x^2=3b^2+a^2 then I put the value of x2 in AB to get sqrt(a^2-b^2) so AB^2+AC^2=a^2=BC^2 so by converse of pythagorean theorem ABC is right Triangled

Sir please make videos for every other topics

Which country?

5:10 and the answer is hmmmmm?? Kinda funny

Molom

What a beautiful introduction to symmedians!! Came here after reading chapter 4 of EGMO :))

Hello sir, just a question. You have won three bronze medals at the IMO. Why is it that you were not able improve to win a silver or gold medal in your second and third attempt. Grestly appreiciate your content and thanks in advice if you repond.

Cannot read this at all

Micheal Penn also has a nice way of explaining problems :>

I wonder how a good graph is the most important part of a geometry problem but no video and no mathematician shows their drawing. They all teach geometry problems using Geogebra and software and no one shows the entire paper process from scratch using a compass, a pen and a ruler. That is strange.

Bro im begginer what i need to do to go to imo what book and problem i need to learn especially problem

Iam fail in my country to join imo bro iam a sad loser

shitty handwriting

Padberg Ways

bro doesn't believe in digital board where he can omit if he overwrites on texts😂

Parisian Spur

The best explaination of this problem! Before this i tried to slove and got it so incorrect as i didn't read over an important detail and when i watched a video on the sol i had alot of doubts. This vedio made it so simple thank you ❤.

great proof, i think you forgot to set X to min({a}_{n+1}^{2^\alpha}) to ensure boundedness tho

5:52 But instead of proving that 5|n⁵-n I can directly say that n⁵-n is divisible by 5 because of fermats little theorem right??

Great story 👏

Don't give up.

I want his channel Excuse me

Hey Shef I am Struggling With Geometric Proofs Can You Provide Some Tips For That?

One of the most underrated channels about maths in youtube

What would be lesson 2? I can't find it

What does mean "homotherapy"? 1:28

one of the worst things in combi

I did it using mod 9 but same

in my solution the key is that xk=xk+9 k is in sub script

How BPB' Is collinear? And is P the midpoint, why? Help me

I am interested in those IMO problems that do not Require much of Knowledge to solve them. I call Them Street smart problems. Does anyone Have any suggestions in this regard? Thanks!

Amazing video. However, where can I find past test papers for olympiads for all levels?