# [IMO 2012 Post 1] Summarizing

Okay I’m a bad blogger for not posting for 1.5 months, but that’s another story.

So, as you might have known, I was going to IMO 2012 in Mar Del Plata, Argentina. If you know my real name, you know that I’m one of the “unlucky” ones of getting a double-digit score and not getting Honorable Mention. Or at least I consider those people unlucky, myself included.

I will begin (or try to) a series of posts retelling how my trip to the opposite side of the world was. (If you don’t get it, I’m in Indonesia and I went to Argentina. Yeah, opposite.) Hopefully. I’m still having jet lag and is now in a half-conscious state, being able to fall asleep at any time.

Warning: This post contains a lot of math stuffs. Read at your own risk.

Best read together with the list of IMO 2012 problems, which can be found at many places but for whatever reason I can only recall AoPS’s one.

Problem 1
Geometry. Long time enemy. I was hoping for geometry being the first problem, and sure. Only angle chasing, right, but I can’t do angle chasing. Time to headbashing.

Problem 2
I also hoped for algebra to appear as second. Doubly perfect. But not inequalities; I suck at them. I was hoping for functional equation, which turned out to appear as Problem 4. A rather difficult insight of breaking a 1 into k-1 1/(k-1)s breaks the problem open, but yeah, difficult insight.

Problem 3
Combinatorics. A perfect distribution I hoped to appear as the first day. But what type of combinatorics is this; stuffs got lying everywhere. I hate liars.

Problem 4
Functional equation. An easy one with only substitutions, and a rather difficult one if you’re not careful. I’m not careful at a very different place instead, for getting minus and plus signs intermixed. Luckily I also submit my scraps which contain one complete solution but scrapped because of being too disorienting (a result numbered (5) appeared earlier than a result numbered (3) 😛 ), which granted me a 6 here.

Problem 5
Geometry. Seems bash-able, and I tried that. But searching for the coordinates of one point gets extremely messy, and I gave up after two hours or so.

Problem 6
Number Theory which is in some way combinatorics-like for being constructing stuffs. But as always, Problem 6’s position as, well, Problem 6 made me shudder. And yeah, the only solution I’ve read includes a +12 induction (that is, inducting from n to n+12). Meh.

End of problems, for a result of 400/600. Next post, when I’m not this tired, will contain the trip to Argentina including the arrival days. Yeah, plural “days”. And also probably a new blog concurrent with this.