Brooke Evans Posted May 4, 2012 Report Share Posted May 4, 2012 This is TZ 2 right? Because TZ 1 was no where near easy. Link to post Share on other sites More sharing options...
Knarik Posted May 4, 2012 Report Share Posted May 4, 2012 (edited) OH MY GOD! THANK YOU!!!!!! I got the area 10 as well! But all my classmates had different answers! Edited May 4, 2012 by Knarik Link to post Share on other sites More sharing options...
Knarik Posted May 4, 2012 Report Share Posted May 4, 2012 Yeah. I had k = 3 and k = -1. But then I plugged both values into the equation and it had to be equal to 0. So I wrote that k = 3 is the right answer. Link to post Share on other sites More sharing options...
vids.10 Posted May 4, 2012 Report Share Posted May 4, 2012 Ahh..thanks....even i got the area as 10...ok...does anyone remember the probability answer of section b? or atleast the last part of the conditional probability thing?? And what were the values of a and b , for the transformation question in section A??? Link to post Share on other sites More sharing options...
Ageha Posted May 4, 2012 Report Share Posted May 4, 2012 The probability about the dice and the white balls?....I think I got 5/11 for the last part.As for the values of a and b, weren't they a=-2, and b = -1? Link to post Share on other sites More sharing options...
HoolaBaloola Posted May 4, 2012 Report Share Posted May 4, 2012 The binomial theorem is not 7! It's 14! Heres even mathematica for more proof: http://www.wolframalpha.com/input/?i=(1%2B(2%2F3)x)%5En(3%2Bnx)%5E2%3D+9+%2B+84x%2C+find+ What was just needed for the binomial was to expand the second bracket and equate it to =9+84x. Not to mention that on IBmemes, 14 is shown to be the more favourable trend. Paper 1 was generally easy actually! However i did a few arithmetic mistakes in probability+area under graph (substituted+integrated correctly but multiplied wrong ). That's all i can think of this paper! Link to post Share on other sites More sharing options...
ro_1293x Posted May 4, 2012 Report Share Posted May 4, 2012 I'm guessing it has been 24 hours? TZ2 was pretty easy! I really didn't struggle with anything much Only the Binomial question was new to me! I got n=21 And I made a stupid mistake with integrating the function for the area under the curve one! :\ I felt like crap when I found out what I did (integrated 13x instead of 13.. so my answer was 6.5(x)2 instead of 13x) And I wanted to ask this. Last part of the last question (for what values of k is y=k ?.. or something like that), what did you guys do there? I said 1/9>k>1 cause local minimum was f(1/9) and local maximun was f(1) and there was this gap there that if k=y for 1/9>k>1 wouldn't touch the graph. Is that right? Overall it was easier than my mock and most IB past papers! I even found it easier than May 2011.. Aiming for 70 to 80 out of 90 Just came back from my paper 2 but can't discuss that now muhahaha! I'm pretty sure it was n=14, that's what whoever could solve it in my class got... was the only confusing question on the whole paper though and that is definitely the value of k that made sense to me too Link to post Share on other sites More sharing options...
vids.10 Posted May 4, 2012 Report Share Posted May 4, 2012 The probability about the dice and the white balls?....I think I got 5/11 for the last part. As for the values of a and b, weren't they a=-2, and b = -1? hmmm...i dont remember exactly but even i got that i guess..for the probability thing... and...the a and b values...yes ....a= -2 and b= -1..yes...same...thanks... And what were the other questions?? Does anyone remember any other??? Oh! and the binomial i didn't get! Link to post Share on other sites More sharing options...
Ageha Posted May 4, 2012 Report Share Posted May 4, 2012 HoolaBaloola, thank you very much. I was looking for that website for ages.Actually, I tried to solve it using both 7 and 14 as values for n. If we considered the first term, both 7 and 14 would give us 9, but for the second term, only 14 could give you a 84x, while a 7 would give you 42x.Does it make sense? Link to post Share on other sites More sharing options...
El Che Posted May 4, 2012 Report Share Posted May 4, 2012 In my opinion, it was one of the easiest P1. Nice to see that most of my results are the same with you guys. I think we only disagree about question 6. I also got n = 14. By the way, do you guys remember what you got for probability question (9)? Especially for b) and c)? Link to post Share on other sites More sharing options...
Ageha Posted May 4, 2012 Report Share Posted May 4, 2012 In my opinion, it was one of the easiest P1. Nice to see that most of my results are the same with you guys. I think we only disagree about question 6. I also got n = 14. By the way, do you guys remember what you got for probability question (9)? Especially for b) and c)? Ahh...Paper 1 wasn't too difficult compared to today's. Remind me again, what was question 9? Link to post Share on other sites More sharing options...
El Che Posted May 4, 2012 Report Share Posted May 4, 2012 Yes, I unfortunately agree with you. It was about a die and probability of getting two white balls from either Bag A or Bag B. In the remaining 5 minutes I found 5/21 for b), and 1/21 for c) and I'm not sure about them. Link to post Share on other sites More sharing options...
Ageha Posted May 4, 2012 Report Share Posted May 4, 2012 I got one as 5/11, I think it was c, as for b....I think it was 11/21....not sure though... Link to post Share on other sites More sharing options...
El Che Posted May 4, 2012 Report Share Posted May 4, 2012 Hmm... Let's see what others have got, though my answer is likely to be wrong. Link to post Share on other sites More sharing options...
HoolaBaloola Posted May 4, 2012 Report Share Posted May 4, 2012 If your final answer is wrong because of all the arithmetic errors, chances are you'd lose one or 2 marks max, so i wouldn't worry too much about it (god bless follow through marks!) Link to post Share on other sites More sharing options...
IB>mindf**k Posted May 4, 2012 Report Share Posted May 4, 2012 (edited) I got n=13 on q7 p1 tz2 but the correct answer n=7; compute different values of n into wolfram alpha and u will see why (put n=7 and you see that the first two terms match, i.e 9+84x, see attached picture) EDIT: Saw that somebody else did it above me (wolfram alpha thing), but n is 7, see above . By the way, if the integration question, I got the area to be 12 instead of 10 due to some wrong arithmetics error, how many points do i get deducted (approximation) Edited May 4, 2012 by IB>mindf**k Link to post Share on other sites More sharing options...
Vincent Casey F Posted May 4, 2012 Report Share Posted May 4, 2012 (edited) As for two equal roots, i think i got k= 3 & -1 too equal roots basically means the same as one answer! so you had to make Delta=0.. which makes k=3 that's why "equal" was in bold font The probability about the dice and the white balls?....I think I got 5/11 for the last part. As for the values of a and b, weren't they a=-2, and b = -1? a=-2 and b=-1 is correct In my opinion, it was one of the easiest P1. Nice to see that most of my results are the same with you guys. I think we only disagree about question 6. I also got n = 14. By the way, do you guys remember what you got for probability question (9)? Especially for b) and c)? Ahh...Paper 1 wasn't too difficult compared to today's. Remind me again, what was question 9? For that question I got massive numbers :\ something like 503/2353 or something like that! didn't have time to simplify And I think n=14 cause so many people got 14.. I don't know :b every 2-3 years there's one question like this that gives all students a hard time! Today's was a joke o.O Edited May 4, 2012 by Vincent Casey F Link to post Share on other sites More sharing options...
ILM Posted May 4, 2012 Report Share Posted May 4, 2012 (edited) As it was said try to expand it and you will find the 7 is the right answer, i used microsoft mathematics, and when i put 7, it gave 84x however when i put 14 it gave me 168xand for the walframalph, the solving is the solution for the equation when it is equal to 9+84x, however the question says 9+84+....... Edited May 4, 2012 by King Glau Link to post Share on other sites More sharing options...
Alejandro Pita Posted May 4, 2012 Report Share Posted May 4, 2012 The answer was n=7, no doubt. Smartest people in my class got 7 and then they explained it to us. I sadly got 14 too. If you use 14, the first term gives you what they ask for, but you would be ignoring the second term. If you use 7, the first term and the second term end up being 9 + 84x.The probabilities of the balls in the bags with the dices... I got 1/21 for the A bag and 4/21 for the B bag, therefore 5/21 chances of getting two white balls. And 1/5 of them would be because of the A bag. Link to post Share on other sites More sharing options...
Liberal Lady Posted May 4, 2012 Report Share Posted May 4, 2012 (edited) Paper 1 in TZ1 wasn't too bad. Question 10 was killer; my teacher hasn't even figured it out yet. Edited May 4, 2012 by Accio Literature Link to post Share on other sites More sharing options...
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