Processing math: 3%
Skip to main content

Posts

Showing posts from July, 2023

My experiences at EGMO, IMOTC and PROMYS experience

Yes, I know. This post should have been posted like 2 months ago. Okay okay, sorry. But yeah, I was just waiting for everything to be over and I was lazy. ( sorry ) You know, the transitioning period from high school to college is very weird. I will join CMI( Chennai Mathematical  Institue) for bsc maths and cs degree. And I am very scared. Like very very scared. No, not about making new friends and all. I don't care about that part because I know a decent amount of CMI people already.  What I am scared of is whether I will be able to handle the coursework and get good grades T_T Anyways, here's my EGMO PDC, EGMO, IMOTC and PROMYS experience. Yes, a lot of stuff. My EGMO experience is a lot and I wrote a lot of details, IMOTC and PROMYS is just a few paras. Oh to those, who don't know me or are reading for the first time. I am Sunaina Pati. I was IND2 at EGMO 2023 which was held in Slovenia. I was also invited to the IMOTC or International Mathematical Olympiad Training Cam...

IMO 2023 P2

IMO 2023 P2 Well, IMO 2023 Day 1 problems are out and I thought of trying the geometry problem which was P2.  Problem: Let ABC be an acute-angled triangle with AB < AC. Let \Omega be the circumcircle of ABC. Let S be the midpoint of the arc CB of \Omega containing A. The perpendicular from A to BC meets BS at D and meets \Omega again at E \neq A. The line through D parallel to BC meets line BE at L. Denote the circumcircle of triangle BDL by \omega. Let \omega meet \Omega again at P \neq B. Prove that the line tangent to \omega at P meets line BS on the internal angle bisector of \angle BAC. Well, here's my proof, but I would rather call this my rough work tbh. There are comments in the end! Proof Define A' as the antipode of A. And redefine P=A'D\cap (ABC). Define L=SP\cap (PDB).  Claim1: L-B-E collinear Proof: Note that \angle SCA=\angle SCB-\angle ACB=90-A/2-C. So $$\angle SPA=90-A/2-C\implies \ang...