Higher Level Maths Paper 1 2012 Before/After

Dazaq · 08-06-2012 06:34PM

im reasonably happy,but didnt get 3c(ii),6c(ii),and i seem to have got the correct answer for integration but dat cant be right cause i was subbing in a's for x's like dere was no tomorrow,very lucky with q5 cause i did dat exact induction dis morning and did a similar binomial aswell,could be a whole lot worse!!!

Dazaq · 08-06-2012 06:35PM

ashh wrote: »

Is it possible for α(squared) + β(squared) in q2 (b) (i) to be negative?... Or is there some complex root trickery afoot?...

i got -6

SellingJuan · 08-06-2012 06:35PM

ashh wrote: »

Is it possible for α(squared) + β(squared) in q2 (b) (i) to be negative?... Or is there some complex root trickery afoot?...

Yea its -6

Frankjones45 · 08-06-2012 06:35PM

Can someone please answer this?

I did Q6 part c (i) out correctly,had second thoughts about it and put a line through it(lightly) ad did it out again but a different method and wrong...Do i still get marks?

Wesc. · 08-06-2012 06:36PM

Dicksboro_man wrote: »

got different ans for those:

1bii = x^3-5x^2+2x+8

4a b=4ac/(a+c)

4bi root(n+1) - 1

could be wrong though also i didnt really try 8c and messed up 6 ciii but ah well..

Hold up I got this guys answers here too.

Dicksboro_man · 08-06-2012 06:37PM

Wesc. wrote: »

Hold up I got this guys answers here too.

as in mine or the other guys?

montown · 08-06-2012 06:39PM

Tankosaur wrote: »

1// (a) a=3 b=-2 c=5
(b)(i) -2,1,3
(ii) x^3 + x^2 -6x =0
(c) was a proof.
(ii) t is a negative number

2// (a) x=3
(b) (i) -6
(ii) 5x^2+-12x+20
(c) proofs

3// proof
(b)(ii) y=-1 x=3
(c) + and - (root3/2 + i/2)
k=1

4// 2ac/c+4 =b
(b) (i) proof
(ii) root n =1 - root n
(ii) 9
(c) proof

5// (a) x=5
(b) (i) 10C r-1 3^11-r 2^1-r x^23-3r
(ii)76545/8
(ii) 23/3 is not rational therefore 23-3r does not = 0
(c) both (i) and (ii) are proofs

6//24x(4x^2)^2
(ii)2/root(9-4x^2)
(b) (i) proof
(ii)6y=x+9
(c)8+4cos4x + 8cos2x
4cos^2 2x + 8cos2x + 8
(2cos2x + 2)^2 >0 thefore all values of fx are increasing

7// proof dy/dx =-1/3
(b) dy/dx = 2y-2x / 4 + 6y -2x
same slopes i.e. m=1/2
(c) different signs for f(1) AND f(0)
3/4 and 1/2
the approximations are repeating

8// x + sin2x / 2 + e^3x /3 + c
(b) 4ln7
(ii) pi/16 - 1/8
(c) a = root k
(ii) area is 5/3 x k^3/2

is that definitely right for the coefficient of x^8? i got something much more regular than 76545/8

Tankosaur · 08-06-2012 06:39PM

Dicksboro_man wrote: »

got different ans for those:

4a b=4ac/(a+c)

4bi root(n+1) - 1

could be wrong though also i didnt really try 8c and messed up 6 ciii but ah well..

Sorry, those are correct as far as I know.

I must have misread when I was typing up

Edit: actually I think 2ac/a+c is still correct

For arithmetic : 2x middle term = 1sr term + 3rd term

so 2/b = 1/a + 1/c
Rhs= c+a/ac
cross multiply to get b = 2ac/(a+c)

Tankosaur · 08-06-2012 06:41PM

montown wrote: »

is that definitely right for the coefficient of x^8? i got something much more regular than 76545/8

I've seen others post that answer, then again others posted different ones too.

Epsi · 08-06-2012 06:42PM

(ii) pi/16 - 1/8

Awesome!

ray giraffe · 08-06-2012 06:44PM

Tankosaur wrote: »

1// (a) a=3 b=-2 c=5
(b)(i) -2,1,3
(ii) x^3 + x^2 -6x =0
(c) was a proof.
(ii) t is a negative number and t not equal to -1 (t=-1 gives 2 equal roots which you don't want!)

2// (a) x=3
(b) (i) -6
(ii) 5x^2+-12x+20
(c) proofs

3// proof
(b)(ii) y=-1 x=3
(c) + and - (root3/2 + i/2)
k=1

4// 2ac/c+4 =b
(b) (i) proof
(ii) root n =1 - root n
(ii) 9
(c) proof

5// (a) x=5
(b) (i) 10C r-1 3^11-r 2^1-r x^23-3r
(ii)76545/8
(ii) 23/3 is not rational therefore 23-3r does not = 0
(c) both (i) and (ii) are proofs

6//24x(4x^2)^2
(ii)2/root(9-4x^2)
(b) (i) proof
(ii)6y=x+9
(c)8+4cos4x + 8cos2x
4cos^2 2x + 8cos2x + 8
(2cos2x + 2)^2 >0 thefore all values of fx are increasing

7// proof dy/dx =-1/3
(b) dy/dx = 2y-2x / 4 + 6y -2x
same slopes i.e. m=1/2
(c) different signs for f(1) AND f(0)
3/4 and 1/2
the approximations are repeating

8// x + sin2x / 2 + e^3x /3 + c
(b) 4ln7
(ii) pi/16 - 1/8
(c) a = root k
(ii) area is 5/3 x k^3/2

Source: I'm a maths teacher!

ashh · 08-06-2012 06:45PM

Dazaq wrote: »

i got -6

That's what I got, but I freaked in the exam 'cause a squared number is always positive?...

Tankosaur · 08-06-2012 06:45PM

Epsi wrote: »

Awesome!

Virtual high five !!

Tankosaur · 08-06-2012 06:46PM

ray giraffe wrote: »

Source: I'm a maths teacher!

Balls, well at least I'll get most of the marks

is everything else more or less right though mr maths teacher man?

emmamurphy233 · 08-06-2012 06:48PM

ashh wrote: »

Is it possible for α(squared) + β(squared) in q2 (b) (i) to be negative?... Or is there some complex root trickery afoot?...

It was -6 I'm fairly sure.

ray giraffe · 08-06-2012 06:52PM

Tankosaur wrote: »

Balls, well at least I'll get most of the marks

is everything else more or less right though mr maths teacher man?

Typo in your answer for Q6: 24x(4x^2-1)^2 !

Dazaq · 08-06-2012 06:55PM

am i de only one who didnt get a decimal in my binomial expansion

Epsi · 08-06-2012 06:55PM

Tankosaur wrote: »

Virtual high five !!

Back at ya! Thought I made a mistake when I got that answer during the exam. Nice to see other people get it as well.

Togepi · 08-06-2012 06:57PM

I'm sure you've all seen the paper online but I'm too lazy to look through the thread. :P It's here anyway for anyone who hasn't seen it.

Tankosaur · 08-06-2012 06:57PM

Epsi wrote: »

Back at ya! Thought I made a mistake when I got that answer during the exam. Nice to see other people get it as well.

Most People I talked to didn't divide by the differential of 2x.

Tankosaur · 08-06-2012 07:00PM

ray giraffe wrote: »

Typo in your answer for Q6: 24x(4x^2-1)^2 !

gracias por favor.

Corrected the error there. Had the answer right anyway.

Just glad I've finally done a decent exam :P

Cruel Sun · 08-06-2012 07:02PM

came in here by accident, thought it was the ordinary paper thread, got fairly worried there for a second when I seen the stuff ye were writing.

kyle84 · 08-06-2012 07:08PM

I got most answers that the guy who posted his exam got. I was annoyed overall though. I went in aiming and expecting 100 %. i needed it because our teacher didn't teach us paper 2. But i think after seeing some of those answers i got an A1. I guessed the k=1 after messing up the first part (switched the coefficients). I think with attempt marks I'll settle in around 275-280

JailB8 xoxo · 08-06-2012 07:16PM

kyle84 wrote: »

I got most answers that the guy who posted his exam got. I was annoyed overall though. I went in aiming and expecting 100 %. i needed it because our teacher didn't teach us paper 2. But i think after seeing some of those answers i got an A1. I guessed the k=1 after messing up the first part (switched the coefficients). I think with attempt marks I'll settle in around 275-280

man you must have been so annoyed dropping those 25 marks

cocopopsxx · 08-06-2012 07:19PM

montown wrote: »

is that definitely right for the coefficient of x^8? i got something much more regular than 76545/8

Do you mind me asking what you got? I got something much more regular than 76545/8 too

Mista · 08-06-2012 07:23PM

cocopopsxx wrote: »

Do you mind me asking what you got? I got something much more regular than 76545/8 too

I got 1260

(i think)

Wanchor · 08-06-2012 07:24PM

cocopopsxx wrote: »

Do you mind me asking what you got? I got something much more regular than 76545/8 too

Noooo! I didn't write it down because it was so ridiculous!

cocopopsxx · 08-06-2012 07:26PM

Mista wrote: »

I got 1260 (i think)

That could be right...one of my friends got the exact same. Damn, I messed up such a nice question

Wanchor wrote: »

Noooo! I didn't write it down because it was so ridiculous!

Really? So annoyed that I messed up such a nice question- was almost sure I got it right. Urghhh!

kyle84 · 08-06-2012 07:26PM

Yes,yes i was

Wesc. · 08-06-2012 07:34PM

cocopopsxx wrote: »

Do you mind me asking what you got? I got something much more regular than 76545/8 too

I got that too. Almost certain it's correct.

** Higher Level Maths Paper 1 2012 Before/After **

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Higher Level Maths Paper 1 2012 Before/After