MAY10 Maths SL Paper 2

[CommeDesEnfants]

Not sure if people want a separate thread for Paper 2 discussion.

What did everybody think of this paper? It seems to be a general consensus that in TZ2, it was fairly better, but in TZ1, it was around the same or a slightly higher level of difficulty.

Incidentally, for TZ1 people: what did everybody put for the very last question on statistics and probability? I always guess when it comes to probability, so I just randomly wrote:

(0.25)(0.7)

------------

(0.866)

= 0.202

It was worth 4 marks... I hope there weren't any other higher thought processes involved.

Also, who disliked the binomial theorem question? I ended up with a seven degree function that I plugged into polysmlt... My calculator took 2 minutes to solve it, and I was so paranoid that it might explode or something. I didn't notice that it said "values" at first, so I was trying to decide on which value to put as my final answer. T_T

Finally, for the acceleration/velocity integration question (considering how much they've asked this in the past few years, I was surprised this was on there), did people find the velocity using radians or degrees? My maths teacher said that they should accept both since the question didn't specify, but I left it in radians to get an answer of around 2.21 or something.

[bLub]

ok, might be a silly question, but just in general: which countries are in TZ 1 and in TZ 2?

[CommeDesEnfants]

I believe the Americas are TZ1, and Europe/Africa/Asia are TZ2. I always say it's an inverse function on the International Date Line.

For future reference, you can check the gibberish on the top of each page of the exam to see if it's TZ1 or TZ2. IT should start with M10 and is followed by some subject information, what group the subject's in, what level you're doing, etc. If you see TZ2, then you're writing the TZ2 exam. If you see TZ0, that means there's only one exam for the entire world, regardless of time zones.

[sweetnsimple786]

OMG P2 was so much harder than P1! I'm TZ1 by the way.

There was no statistics on P1, which was a blessing, but they made up for it on this one

For the probability, I did the same thing as you, but I didn't get the denominator you got. I think I messed up somehow before the last step because my friend got the same thing as you, I think.

And yes, the binomial theorem one was ridiculous. The first three parts were so easy and then there was a 7th degree polynomial?!

I'm so used to polysmlt but we had to have our calculators cleared, so the ones we used didn't have that app =/

We had equation solver, which I stumbled upon by accident. I didn't know how to use it and I got a number greater than one for it because apparently you have to guess a number close to it to use equation solver. What the heck?

Anddd I missed something on the very first problem. The matrix one. Ugh I forgot you could press the -1 button to find the inverse of a matrix on a TI calculator. I'm so ridiculous.

And for the acc/vel question.. I don't remember using theta... can you remind me? I remember it was like ln of abs value of t plus some other stuff, I think...

[kelly lien]

I wrote .202 as well for the probability question, think that's right as a lot of other people got that as well.

For the binomial, i ended up writing 7 choose 4 (p)^4 (1-p)^3 and expanding that for work, and then it turns out I couldn't solve it after that. So I kept trying values in my GDC until I got .368 or something like that, and it worked so I put that. (I DID get the seven degree function you mentioned).

For the acceleration I got the same answer as you, leaving it in radians - we should be okay.

The cosine wave took me way too long. And it turns out that I got the amplitude and the period wrong anyway; it was a reflection on the x axis and I didn't realise . I got that k = -3 though.

[sweetnsimple786]

Was the amplitude like 5 and equilibrium [or the vertical shift] 2? I couldn't remember if I should add the values at the crest and trough or subtract them...

[kelly lien]

The amplitude was actually -5, I missed that as well. The vertical shift was 2, and the period was pi/4 .. Stupid me left it as 8.

[sweetnsimple786]

-5? Crap. Was the graph flipped upside down or something?

And I got pi/8, too. Isn't the period equal to 2pi/b? Where b is a*cosbx + c

[CommeDesEnfants]

Yeah, the graph was flipped. It started at a "minimum" and it was a cosine graph, but I didn't notice until I graphed the function and went... wtf? I usually finish my math papers in about 40-45 minutes (thank you, sympathetic nervous system), so I had a lot of time to go back and check stuff.

Sweet: polysmlt should be an allowed application! My math teacher checked everybody's calculator before the exam and cleared every program except for that and another.

Kelly: Graphing was also an option, too. I think there were supposed to be two answers, though; I got 0.3something and 0.7something. Both worked, and the question did say "values" of p. I think you also mean that the period was 8, and the value of "b" or whatever was supposed to be pi/4. Ah well, I'm sure you'll at least get one mark for recognizing that the period was 8, anyways.

I was surprised that they didn't ask any money questions. I'm totally rubbish at them, and they haven't asked them for quite a while. Glad we dodged that bullet.

Edited May 7, 2010 by CommeDesEnfants

[kelly lien]

I don't understand how two values were possible, because if it was the 0.7 something you said, wouldn't that make it impossible to get .15 as the probability? That's why I disregarded my other value =/ Yeah, my b value was wrong, because I originally wrote that b = pi/4, but because my amplitude was wrong, my graph was wrong as well, so I changed it back to 8

Other than that, I think I did decently

[CommeDesEnfants]

If you plugged in 0.7whatever into the binomial distribution expression, you still ended up with 0.15. Oh, the magic of mathematics.

[mimii]

i don't remember any of the questions you're mentionning and i live in Ottawa ahahah!

i had questions on bacterias at one point and question 9 was a long vector question and question 8 was about sectors and the length of the arc. anyways i liked paper 1 better..

[charlotteee]

i don't remember any of the questions you're mentionning and i live in Ottawa ahahah!

i had questions on bacterias at one point and question 9 was a long vector question and question 8 was about sectors and the length of the arc. anyways i liked paper 1 better..

Haha, that was the TZ2 paper..! It had the rate of change, as 800e^0.13 or something, on the vectors question you had to find the value for a, given that the angle was 40! What did you get for EF on that?

[Einstein's Grandson]

GOD! I HATED that question! Ye know how teachers sometimes tell you that every exam has one helluva question that's basically designed to test whether or not you know how to use the GDC? I think this one was it. I just substituted the equation for the Cos of the angle into a function and made it equal to zero, so I can calculate both values of A. I graphed that function and made the GDC calculate the x-intercepts of the function and just used those as an answer. That test was torture. I didn't answer the very last question, the one worth 14 marks, because I got stuck on the geometry one right before. Stupid...

[Sierra.tehe]

TZ2 Paper 2 was soooo much better than paper 1... I had a smile on until I realized I had psyc in a couple hours!

[mimii]

i don't remember any of the questions you're mentionning and i live in Ottawa ahahah!

i had questions on bacterias at one point and question 9 was a long vector question and question 8 was about sectors and the length of the arc. anyways i liked paper 1 better..

Haha, that was the TZ2 paper..! It had the rate of change, as 800e^0.13 or something, on the vectors question you had to find the value for a, given that the angle was 40! What did you get for EF on that?

yea exactly! omg.. umm i think i messed up cause i got something like plus or minus square root of 14 for the value of a

what did you get for the rate of change.. i wasn't sure what i was supposed to do..

and what's EF?

[Austin Glau]

OMG P2 was so much harder than P1! I'm TZ1 by the way.

There was no statistics on P1, which was a blessing, but they made up for it on this one

For the probability, I did the same thing as you, but I didn't get the denominator you got. I think I messed up somehow before the last step because my friend got the same thing as you, I think.

Yeah, I agree. I was happy that there was almost no statistical stuff on paper 1, but Paper 2 was full of it, and it was a lot harder for me, mainly b/c i didn't study for the probability a lot, it wasn't really covered at all in Mahs HL.

[bumblebeee~]

Paper 2 TZ1 was death in 11 pages.

My math teacher told me afterwards that all you had to do for the binomial distribution question was to plug the two functions (the one you set up, and y=0.15) to determine the value of p... something like that.

the last probability question was worth 4 marks? o.o

[Tilia]

TZ2 Paper 2 was soooo much better than paper 1... I had a smile on until I realized I had psyc in a couple hours!

Are you serious? P1 was so easy, I feel as if I could score full marks on it (almost), but P2 took so much time!

[Peachez]

TZ2 Paper 2 was soooo much better than paper 1... I had a smile on until I realized I had psyc in a couple hours!

Are you serious? P1 was so easy, I feel as if I could score full marks on it (almost), but P2 took so much time!

For me papaer 2 was also better than paper one. It did take more time, but the problems did not as seem as difficult. Perhaps because I focused my attention on the topics that were covered in paper 2.

Edited May 11, 2010 by Peachez