IB Maths HL 2012

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The trig one was fine I multiplied the top and bottom by (CosA+SinA) and the answer presented itself. I think there were other ways too.

Reply 21

Hyaline

Original post by MAMDS1993

oh the xy=6 x^2-y^2=5 ??

What number was this? Q10 anyone xD, got the answer but it was only 7 marks........ I feel like it should have been at least 8 or 9.

Reply 22

MAMDS1993

I tried qn 10, I got up until the limits i got 1/2(e^(-x)sinx - e^(-x)cosx) and then put in the limits and ran out of time before I could complete..but I feel like I would've gotten it with abit more time! the xy=6 and x^2-y^2=5 was number 12! the complex number question where u had to find the roots of that number and its conjugate!

Reply 23

chjooo

What do you guys think the grade boundaries for 7 and 6 are gonna be for paper 1?

(edited 11 years ago)

Reply 24

arra

95 for 7. I never really pay attention to the 6 boundries so can't guess, sorry.

Did anyone else, in the complex numbers, get something weird for the argument like arctan((root7)/3 or something).

Reply 25

dogmatichurricane

Original post by arra

95 for 7. I never really pay attention to the 6 boundries so can't guess, sorry.

Did anyone else, in the complex numbers, get something weird for the argument like arctan((root7)/3 or something).

It varies tremendously especially with HL Math. I've seen it go anywhere from 80 to 100.

Reply 26

arra

Original post by dogmatichurricane

It varies tremendously especially with HL Math. I've seen it go anywhere from 80 to 100.

I've seen it at 74 on some papers. And today's Paper 2 was harder than those paper's for sure.

But this paper one was certainly on the easier side, so I'm guessing 95.

Reply 27

dogmatichurricane

Original post by arra

I've seen it at 74 on some papers. And today's Paper 2 was harder than those paper's for sure.

But this paper one was certainly on the easier side, so I'm guessing 95.

Ah fair enough - I wouldn't think too much about it though. I came out of my papers last year thinking Paper 1 was straightforward and Paper 2 had the most messed up section B I had ever seen. Paper 1's grade boundary came out at 79 and Paper 2's was 84 or something along those lines if I remember right. Each to their own I guess....

Reply 28

Saymyname!

Original post by TTGenius

the one u have to transfer to e^(iθ) form, anyone have ideas ????

Ok, I took my time to write this out for you guys :smile:

Reply 29

emilsemils

Guys low lets estimate the difficulty of paper 1 by a scale from 1 to 10 (1 easy to 10 hard)

Reply 30

Hyaline

I got the roots for the 5+2i, revised that the night before :biggrin:

. I'd give it an 8 in relative terms, usually I find P1 easier than P2 for this year it was the opposite. I don't remember them exactly they were 2, -2 and 3i I think.

(edited 11 years ago)

Reply 31

Saymyname!

Paper 1 section A was a 3 or 4. Section B was a 5.

Reply 32

MAMDS1993

Original post by Saymyname!

Ok, I took my time to write this out for you guys :smile:

Oh I got that question pretty much then except i didn't put pi - and pi +! I put 2e^(i(arctan(root(7)/3)) and 2e^i(arctan(-root(7)/3))! Which is I suppose the same thing because pi plus gives u a positive sign and pi minus gives u a negative sign!

Reply 33

MAMDS1993

yeah -5+12i was (2+3i) or (-2-3i) and -5-12i (the conjugate i guess) was (2-3i) (-2+3i)!

Reply 34

MAMDS1993

People in my class didn't like paper 1..so its not everyone of us who thought it was okay! May 2009 TZ2 Paper 1 is one of the easiest papers I have ever seen and the boundary for that is 91! Even though our paper 1 was pretty good, I'd still say May 09 TZ2 P1 was way easier!

Reply 35

Hyaline

Was it 5+12i or -5+12i?

Reply 36

Banna

Original post by Saymyname!

Ok, I took my time to write this out for you guys :smile:

That is quite relieving....I got exactly that..at least all the answers look familiar

for the equation at start of part B

I got (x+4)(x-2)(x^2 + 3x +4)

Reply 37

Saymyname!

Original post by Banna

That is quite relieving....I got exactly that..at least all the answers look familiar

for the equation at start of part B

I got (x+4)(x-2)(x^2 + 3x +4)

well done! I got the same equation!