Higher Mathematics : Paper Two Opinion

seandoiler

cocoa wrote:

not disagreeing with you here, but could you tell me where? (I'm also assuming you mean 2(c)(i) paper 2...)

or you could just edit it yourself and fix it

no it's paper 1 Q2 (c) (i)....when you multiply across by x+2....you should get 4x+8 (you had 4x+4)...and the final answer is (x-1)^2 >/= 0...i've edited it on the page..hope you don't mind

cocoa

seandoiler wrote:

no it's paper 1 Q2 (c) (i)....when you multiply across by x+2....you should get 4x+8 (you had 4x+4)...and the final answer is (x-1)^2 >/= 0...i've edited it on the page..hope you don't mind

ah, correct. Thanks for the fix

Feddd

In my Q4 c(ii) I used the same logic as others who have gotten it out but second last line I had: 2pi(Rads) +180Sin2A=90pi. If I divide accross by 180, that cancels the pi in (2pi(rads)) right?

And in case anyone was wondering: In Q2 b(ii) if you got 5/4(root3) you are right aswell. Everyone else seems to have gotten 5root3/12. Both answerd are the same but my answer is got if you write 3/root 3 as root3(Thought it made the multiplication easier).

cocoa

Feddd wrote:

In my Q4 c(ii) I used the same logic as others who have gotten it out but second last line I had: 2pi(Rads) +180Sin2A=90pi. If I divide accross by 180, that cancels the pi in (2pi(rads)) right?

well, yes, 180 degrees = pi radians but it's a really really bad idea to mix degrees and radians in the one equation. I honestly can't really make out what you mean by the equation you gave. when you say 2pi(rads) do you mean just the pure angle, and by 90pi, do you actually mean, literally 90pi?

Feddd

cocoa wrote:

well, yes, 180 degrees = pi radians but it's a really really bad idea to mix degrees and radians in the one equation. I honestly can't really make out what you mean by the equation you gave. when you say 2pi(rads) do you mean just the pure angle, and by 90pi, do you actually mean, literally 90pi?

Not sure how I got the eqn to be so messy but its just the way things turned out.
For the area of the sector I said that 2A degrees is 2Api/180 rads and did out the area of a sector formula and after cancelling it turned out to be 2pi but because of the way I did it that was in terms of rads.
And the 90pi was indeed 90pi. Can't remember how I got it that way and cba working it out now. ^^

charlie1234

Q4 (c) (ii), I ended up with the right answer, but I realised after the exam, it was the wrong method:

I said, since the area of the semicircle is bisected by [ac], then the area of triangle acb and the sector acb = the area of the semi-circle (I know its completely wrong)

So I said that:

(1/2)(2rcosA)(2rsinA) + (1/2)(2r)^2(A) = (1/2)(pi)(r^2)
= sin2A + 2A = (pi)/2

I was thinking afterwards, could you not draw a circle with a as the centre and radius of 2r? But then that would leave you short of the space between the circumference and [cb] wouldn't it?

Although, the stumbling block being that I didn't actually draw in an extra circle.

....Or is it just me hoping against all hope?:D


P.S, do you think Q6 (a) (ii) and Q7 (a) (ii) will be given attempt marks or the Hit/Miss thing?

JC 2K3

charlie1234 wrote:

I was thinking afterwards, could you not draw a circle with a as the centre and radius of 2r? But then that would leave you short of the space between the circumference and [cb] wouldn't it?

That was my mistake and why I ****ed up, I took the radius to be rcosA though, how I didn't realise that 2rcosA wan't equal to 2r I don't know...

My equation was (1/2)(r^2)(cos^2(A)).(A) = (pi)r^2/4
Which simplified to: pi/2 = cos^2(A).(A)
The I converted cos^2(A) to (1 - sin^2(A)) and kept messing around with it, although in fact I'd gotten (rsin2A)/sin(A))(equals 2rcosA) for the first part, and that made things even more messy.

Optimistically i could be looking at 7/10, since I realised how to do it, put brackets around my other work and drew a diagram of what I should have done with 2 mins to go. Pessimistically, it could be 3/10....

charlie1234

Yeah, hopefully they'll go easy on us:)

I really need every mark I can get now for my A1, stupid Q6 on Paper 1 completely screwed me over

(got c(i) wrong and thus thought my ways for doing part (ii) and (iii) were completely wrong when in fact they were perfectly correct)

I'd be surprised if I got over 30 on that question. Still confident of 94+% on P2 though:D

JC 2K3

I'm confident of 93/94% on paper 1 and about 88% on paper 2...

(93 + 88)/2 = 90.5%

Which means I've probably just barely got it.

carlowboy

I calculated exactly 270 in paper 2 and about 274/5 in paper one which would just be about enough. Not positive on that btw!

SamHamilton

I reckon I got 252 on Paper 1 with 3 attempt marks in the questions in which I didn't get the right answers but I think I might get more for some. 252 + 7 for answering in Irish brings me up to 259 and that gives me 86% on Paper 1, by my reckoning.

Paper 2 I reckon I got 256. 256 + 7 for Irish is 263 which gives me 87.6%.

So that gives me 87% altogether. That's if the marking stays the same though but it almost always changes. We'll never really know until August.

charlie1234

JC 2K3 wrote:

I'm confident of 93/94% on paper 1 and about 88% on paper 2...

(93 + 88)/2 = 90.5%

Which means I've probably just barely got it.

I've calculated (hopefully) :

260 in P1 and 284 in P2 which is about 90.6% - depends on me getting some attempt marks for some stuff though. I'd be disappointed if I didn't get it - 96% average in mocks:D