CataMorales Posted May 7, 2010 Report Share Posted May 7, 2010 How did you solve the equations 6+6 sin x = 0 and 6+6 sin x= 6 that got me very confused. Quite a nasty paper, but I hope I will get the marks for methods e.t.c. and hopefully there have been enough silly people to keep the boundaries low.6sinx= -6, and that's the same as sinx = -1 ,but amplified. So x was 3pi/2 Reply Link to post Share on other sites More sharing options...
CataMorales Posted May 7, 2010 Report Share Posted May 7, 2010 Did any of you did number 5 or 6? (can't remember what section) the one you had to find the intersection of the derivated function with the x-axis but there was no function! just some points on the graph... Reply Link to post Share on other sites More sharing options...
CommeDesEnfants Posted May 7, 2010 Report Share Posted May 7, 2010 Did any of you did number 5 or 6? (can't remember what section) the one you had to find the intersection of the derivated function with the x-axis but there was no function! just some points on the graph...Oh goodness, I heard about this TZ2 question. Were the coordinates of the max and min given? If so, wouldn't the derivative cross the x-axis at the same x-values as the max and min? Or, were there no coordinates at all.. Reply Link to post Share on other sites More sharing options...
jnguyen18 Posted May 7, 2010 Report Share Posted May 7, 2010 TZ1 - the integral question which had a function of 16-4x^2 (i believe) boundaries of -2 to 2 had a volume of 128pi/3. i checked it on my calculator immediately following the exam im 99.99999% that's the answer so that can be one less thing to worry about Reply Link to post Share on other sites More sharing options...
IB_sucks Posted May 7, 2010 Report Share Posted May 7, 2010 yeah, that's correct.. I'm pretty confident about that one! how did you do on the probability question?I'm pretty sure that the IB made a mistake in that question, and it got me stuck and I lost around 20 minutes (causing me not to have enough time for the exam)...It said that Jose misses the bus 2/3 times, and 1/3 times he obviously catches it. But then, in that table you had to copy and complete, under 0 euros, it should have been:(probability of missing the bus) * (probability of missing the bus)= 2/3 * 2/3= 4/9when they put that it was 1/9...Can anyone confirm this? I'm thinking about going to talk to my teacher...Your completely wrong, the IB DID NOT get a question wrong. I was able to get it right, i think that you flipped the probabilities of missing and not missing the bus. I truly cant remember the numbers now, but based on the probabilities of what you just said, it seems like the probability of missing is 1/3 and not missing is 2/3. I do remember what the table was like: X 0 3 6 P(X=x) 1/9 4/9 4/9 Reply Link to post Share on other sites More sharing options...
uhm&ahh Posted May 7, 2010 Report Share Posted May 7, 2010 Did any of you did number 5 or 6? (can't remember what section) the one you had to find the intersection of the derivated function with the x-axis but there was no function! just some points on the graph...Hmmm was that the last question in section A? When there's a local min or local max then f' = 0 so at those points the derivative should cross the x-axis. I was also a bit confused when I saw the question at first but I think thats how you do it. Reply Link to post Share on other sites More sharing options...
Thunder Posted May 7, 2010 Report Share Posted May 7, 2010 So what did u guys get for the area of the shaded region in the last question? Where you had to express it in terms of pi?I got 9pi I got 9pi too!hey,what was that question again?thanks for the help Reply Link to post Share on other sites More sharing options...
kelly lien Posted May 7, 2010 Report Share Posted May 7, 2010 Okay, I think paper 2 can be discussed now... Anyone else think it was way harder than the last few years' previous papers? I was getting high 7s and sometimes even perfect with those, and with this one I'm not even totally sure I'm getting one! I don't think I screwed up too badly, but Paper 2 made a LOT of my peers uncomfortable with how difficult it was, especially in comparison to Paper 1 Reply Link to post Share on other sites More sharing options...
luiz Posted May 7, 2010 Report Share Posted May 7, 2010 Okay, I think paper 2 can be discussed now... Anyone else think it was way harder than the last few years' previous papers? I was getting high 7s and sometimes even perfect with those, and with this one I'm not even totally sure I'm getting one! I don't think I screwed up too badly, but Paper 2 made a LOT of my peers uncomfortable with how difficult it was, especially in comparison to Paper 1 Hmm. Seemed much easier to me than previous ones, because it only had a single question about probability, and those are usually hard. Reply Link to post Share on other sites More sharing options...
calsbo Posted May 7, 2010 Report Share Posted May 7, 2010 Okay, I think paper 2 can be discussed now... Anyone else think it was way harder than the last few years' previous papers? I was getting high 7s and sometimes even perfect with those, and with this one I'm not even totally sure I'm getting one! I don't think I screwed up too badly, but Paper 2 made a LOT of my peers uncomfortable with how difficult it was, especially in comparison to Paper 1 TZ1? I thought it was difficult. I had to spend too much time thinking about how to solve the problems, that I didn't have time to finish the last sections of 8, 9 and 10; I moved on when I had to spend too much time. Section A was good though I think, except for that problem where you had to find the transformations of the cosx graph, I didn't have time to figure that out but still spent too long on it. I would definitely have been able to answer every question in an un-timed situation which is why I'm really frustrated. I never got anything bellow a 93% on a test in the course and now I'm afraid that I really screwed up paper 2. I guess we just have to hope for low grade boundaries, but who knows what will happen. Reply Link to post Share on other sites More sharing options...
Dzeb Posted May 7, 2010 Report Share Posted May 7, 2010 (edited) So what did u guys get for the area of the shaded region in the last question? Where you had to express it in terms of pi?I got 9pi I got 9pi too!hey,what was that question again?thanks for the helpAre you guys sure? The function was 6+6sinx and boundaries were 0 and 3pi/2. Integrating the function gives us 6x - 6cosx. Therefore, we get:6(3pi/2) - 6cos(3pi/2) - 6(0) + 6cos(0) = 9pi + 6Correct me if I'm wrong, but I'm pretty sure that it's right Edited May 7, 2010 by Dzeb Reply Link to post Share on other sites More sharing options...
emmak Posted May 7, 2010 Report Share Posted May 7, 2010 Are you guys sure? The function was 6+6sinx and boundaries were 0 and 3pi/2. Integrating the function gives us 6x - 6cosx. Therefore, we get:6(3pi/2) - 6cos(3pi/2) - 6(0) + 6cos(0) = 9pi + 6Correct me if I'm wrong, but I'm pretty sure that it's rightI got 9pi + 6 as well!!! ^^ I've been lurking around here trying to make myself feel better about how the exams went (overall pretty good, just those little mistakes are wracking my brain!)... and I'm 100% sure that this is the answer I wrote down. Can't remember the equation or anything... any opinions on this??? 9 pi or 9pi + 6? Reply Link to post Share on other sites More sharing options...
pomoni Posted May 7, 2010 Report Share Posted May 7, 2010 i think it was something plus 6 too... Reply Link to post Share on other sites More sharing options...
SiNnert. Posted May 7, 2010 Report Share Posted May 7, 2010 I got 9pi + 6 too... I'm still pretty unsure bout the answer for this one tho, so which one's correct? Reply Link to post Share on other sites More sharing options...
jnguyen18 Posted May 7, 2010 Report Share Posted May 7, 2010 TZ1 - in comparison to paper 1, i thought paper 2 was much harder compared to the previous years, most notably section B with that very last data question. hopefully the boundaries are lower this year Reply Link to post Share on other sites More sharing options...
HanoBee Posted May 7, 2010 Report Share Posted May 7, 2010 In P1 TZ2 there was this question about finding vector BC. They gave you AB and AC I think. I spent 10 minutes trying to figure out how to do that. I suck at vectors. Paper2 was slightly easier but counting the things I'm sure I did right in the paper it was a total of 50 out of 90 (I think?). God, I just hope I don't fail Reply Link to post Share on other sites More sharing options...
HanoBee Posted May 7, 2010 Report Share Posted May 7, 2010 yeah, that's correct.. I'm pretty confident about that one! how did you do on the probability question?I'm pretty sure that the IB made a mistake in that question, and it got me stuck and I lost around 20 minutes (causing me not to have enough time for the exam)...It said that Jose misses the bus 2/3 times, and 1/3 times he obviously catches it. But then, in that table you had to copy and complete, under 0 euros, it should have been:(probability of missing the bus) * (probability of missing the bus)= 2/3 * 2/3= 4/9when they put that it was 1/9...Can anyone confirm this? I'm thinking about going to talk to my teacher...Your completely wrong, the IB DID NOT get a question wrong. I was able to get it right, i think that you flipped the probabilities of missing and not missing the bus. I truly cant remember the numbers now, but based on the probabilities of what you just said, it seems like the probability of missing is 1/3 and not missing is 2/3. I do remember what the table was like: X 0 3 6 P(X=x) 1/9 4/9 4/9at first for the 6 i got 6/9 but then i added them up and they were more than 1 so i was like wth o.o but as far as i can remember i got the same combination you did, 1/9 4/9 4/9 Reply Link to post Share on other sites More sharing options...
Lara.z Posted May 7, 2010 Report Share Posted May 7, 2010 i screwed up so badly... i don't know what to do... i felt that there were too many questions to answer in so little time...! everytime i think about it i want to kill myself URGH mutual feelings anyone? i really don't want to resit :'( Reply Link to post Share on other sites More sharing options...
CommeDesEnfants Posted May 7, 2010 Report Share Posted May 7, 2010 In P1 TZ2 there was this question about finding vector BC. They gave you AB and AC I think. I spent 10 minutes trying to figure out how to do that. I suck at vectors. Paper2 was slightly easier but counting the things I'm sure I did right in the paper it was a total of 50 out of 90 (I think?). God, I just hope I don't fail I'm fairly certain that if you flip AC to make it CA and then add that to AB, you can find BC. If you've ever taken Physics, vectors makes much more sense. Reply Link to post Share on other sites More sharing options...
luiz Posted May 7, 2010 Report Share Posted May 7, 2010 In P1 TZ2 there was this question about finding vector BC. They gave you AB and AC I think. I spent 10 minutes trying to figure out how to do that. I suck at vectors. Paper2 was slightly easier but counting the things I'm sure I did right in the paper it was a total of 50 out of 90 (I think?). God, I just hope I don't fail I'm fairly certain that if you flip AC to make it CA and then add that to AB, you can find BC. If you've ever taken Physics, vectors makes much more sense. Yeah; or simply subtract AC from AB to get BC. (same thing as you just said but expressed a bit simpler) Reply Link to post Share on other sites More sharing options...
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