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Re: HSC 2012 Marathon :) I found that one much easier. Now back to this stupid hexagon >.< $Time taken for projectile B to fall h metres is given by $h = \frac{1}{2}gt^2$ \implies $t = \sqrt{\frac{2h}{g}}$. \\ \\ Time taken for projectile A to reach max height is given by $\.{y}=0$ \implies...

Re: HSC 2012 Marathon :) I think that question is missing information. Right now it's just a scenario with two unrelated projectiles. Do they hit each other or something?

Re: HSC 2012 Marathon :) For Sy's projectile problem (this is quite a convoluted method): $The concave-down parabola representing the path of the projectile has a root at x=0 and a maximum at $x=h$. Symmetry of parabolae dictates its roots are 0, 2h. Hence it is of the form $y=-ax(x-2h)$...

Re: HSC 2012 Marathon :) the derivative cos(x) + 1 is always >= 0 so f(x) is always increasing, so it has at most one root. f(0.4) < 0, f(0.6) > 0, so f(x) = 0 for some 0.4<x<0.6. Then just halve the interval. How do you do math notation?

Ooh another question... are we allowed $\mathrm{cis} \theta$ notation or do we have to expand it as $\cos \theta + i \sin \theta$? (and how do you do latex on this forum?)

lol people can know who I am, Goldy is my nickname in real life too. EDIT: hurry up and message me. I'm guessing I know you from one of the Australian olympiad teams.

You know me? Cool, who are you? No one at my school does Latin or Greek.

Not trolling, just competitive and surrounded by other competitive people.

That's what happens to me too. I keep a list of questions that I wasn't able to do immediately, and in the last few minutes I go through that list and get as many marks as possible from those questions. There are usually about 5-10 marks I can't get at all and 5-10 marks worth of silly mistakes.

First I had included my aims in each subject, then I thought I'd push myself and make those aims higher, but then on reflection they were way too high, so I just removed that section completely :) I also had ranks for each subject in my signature a while ago, but there are a few subjects where...

I think I'm capable of doing most or all of the questions on the paper, but on past HSCs I almost always run out of time. This is becoming very frustrating. My current technique: when I'm going through the paper, if a question seems to be taking too long, I note it down and come back to it...

Have you seen projecteuler.net? It seems like the sort of thing you'd be interested in.

Adam Spencer, the radio host, famously got 200/200 on 4u in the 1980's. Last year the top in state in 3u was a year 11 accelerant who got 100%. He got 99% in 2u.

It's quite similar to MX2 HSC 2007 8c).

yep, sorry :) I don't know the proper editing etiquette for BOS.

what you have quoted there is 3 groups of 4.

I think it's (12C4 * 8C4) / 3! Choose 4 from the initial 12, then 4 from the remaining 8, then the remaining 4 are their own group. Then, to make the ordering in which you chose the groups unimportant, divide by 3!. EDIT: this is easier to see for a smaller case. Consider picking 2 groups of...

One more...

Another one! Tangent Points Point A lies at the coordinate (3; 8). Find all the points P on the curve y=x^2 such that line PA is tangent to y=x^2. Solution:

You want maths? I'll give you maths. Good luck.