The 2004 HSC - Mathematics Extension 2 Paper (2 Viewers)

[vi9ilante]

lol...the test was insultingly EASY!! at least 110 by my calculations..far out! i cant believe i mistook the absolute vaule sign for a modulus! >.<


P.S. Sefton High..Sux..Hard..

 

[SeDaTeD]

But the absolute value is the modulus, just the distance from the origin.

 

[vi9ilante]

lol of course..but that meant i drew a circle...and so didnt take two cases for it...
T_T

 

[Estel]

P.S. Sefton High..Sux..Hard..

you think?

but that came out of nowhere

 

[vi9ilante]

Obtw, how many of u guys got tricked by the partial fraction integration...? i nearly made a mistake there...*phew

 

[Rorix]

uh, what was the trick?

 

[redslert]

that is a really really easy test in comparison to last year!!

the hardest question i can see is just the circle which took me a while
question 8 was eh, repeat and also part b was do-able!
question 4 conics would have took a lot of time doing algerbra

overall the exam is very textbook like

 

[kcVFrOgg]

Insultingly Easy!!

lol...the test was insultingly EASY!! at least 110 by my calculations..far out! i cant believe i mistook the absolute vaule sign for a modulus! >.<

Vigilante aka danny u fag.. ur right... HOW EASY WAS THE TEST?!?!! i feel sorri for u, onli 110??
u relli are like the dumbest in sefton
i expect half the state to get like 115

 

[Rorix]

the q4 conics algebra wasn't really complicated..

first part is just sub (ae,0) into chord of contact and show xo = a/e
then if T lies on x axis, through the tangent equation you prove P, Q lie directly above/below the focus
then PS/ST is just a straight line PS=y, ST = a/e - ae
simplify that by subbing x=ae, y=? into the ellipse equation, from memory y=b^2/a or something (using eccentricity definition)
then gradient of the lines = +-e, e<1 and the angle the line makes with the axis is arctan e
so PTQ is 2arctan e
e<1
so PTQ< 90
i forgot what the last part was...oh yeah, area of the triangle
since ST is perpendicular to PQ, ST is your perpendicular height (already found earlier) and PQ is your base length (=2y)
so area of the triangle is y*ST

trick is realising that PQ is parallel to the y axis i think

 

[vi9ilante]

i agree with u there dude..!! Very straightforward..no need for mathemagicks ^^
Oh it was that the denominator in the partial fraction didn't match LHS..so u had to do some simplifying first. Geez i did those so systematically with practice papers and nearly overlooked it.

 

[Rorix]

what's wrong with the good ol' multiply by (x-1)^2(x+1)? maybe i need to look at the paper again...


or actually go do something useful lol

 

[vi9ilante]

Stfu kcvfrogg...sorryyy ur like wut...top five in Sefton?! Geez SimonL, betcha ur gonna get pwned in English...by ME...lol.
By the by, wut did you get for the last two questions in 8?! Far out dude, i only had 15minutes to work on that one!

 

[Estel]

The question

(x^2-7x+4)/[(x+1)(x-1)^2] = a/(x+1) + b/(x-1) - 1/(x-1)^2

no tricks?

 

[shazzam]

err, double partial fractions? Though tis probable that I did it in a longer way than needed

 

[kcVFrOgg]

Dh

Stfu kcvfrogg...sorryyy ur like wut...top five in Sefton?! Geez SimonL, betcha ur gonna get pwned in English...by ME...lol.
By the by, wut did you get for the last two questions in 8?! Far out dude, i only had 15minutes to work on that one!

yeh u prob gonna get liek 100 for sure, ill prob hav to do wit 98. damn...
last 2 questions... omg they were the first questions i attempted, finished them in like 2 min
sorry bro i forgot

 

[Estel]

(x^2-7x+4)= a(x-1)^2 + b(x+1)(x-1) - (x+1)
:. 4a = 12
a = 3
b = -2

i don't see a trick....

 

[mervvyn]

Well.... that was a bit depressing as exams go, although to be expected in 4u, even if some people claim it was easy. i haven't counted up yet, but i think ~80-85 would be about right. I left a lot of stuff out, and got mental blocks too often for my liking. Ah well. Best of luck to you in 3u, kick some arse.

 

[mojako]

well probably the trick is not everyone has done partial fraction where it has a linear factor raised to a power of greater than 1. In this Q it's the (x-1)^2 factor. So if the identity is not given not everyone may be able to do it (and btw the syllabus says this case is not to be considered but its been asked several times)

but in this paper the identity is given. u just need to multiply it by the denominator on the LHS and there is no trick.

 

[Estel]

oh!

ok.

try this:

http://mathworld.wolfram.com/PiFormulas.html

feel better now?

That's 1 q...
spending 100 hrs on number theory vs 100 hrs on syllabus topics...
can see which would be time better spent.

might i add it didn't need anything but integ. knowledge anyhow, so readin it b4hand would be of no help.

 

[shazzam]

oh!

ok.

try this:

http://mathworld.wolfram.com/PiFormulas.html

feel better now?

Right. You really were too close to the action methinks...