Guest Posted May 4, 2012 Report Share Posted May 4, 2012 As for two equal roots, i think i got k= 3 & -1too equal roots basically means the same as one answer! so you had to make Delta=0.. which makes k=3that's why "equal" was in bold fontI took two equal roots to mean the discriminant = 0 (b^2 - 4ac) because that gives one repeated root, so there would, technically, be two equal roots. So that would mean that the x values have to be the same, not the k ones - right? Since k is the constant, not the variable.I could be completely wrong here, but that's what I took it to mean and how I approached it. I found that both k = 3 and k = -1 led to one repeated root (they led to (x-1)^2 and (x+1)^2 I think), so I kept both of them in. Link to post Share on other sites More sharing options...
shinnmoso Posted May 5, 2012 Report Share Posted May 5, 2012 For that dreaded binomial expansion question, I think my friend solved it after the exam. For those who are interested, here is the solution. (Sorry if I break your monitor) Link to post Share on other sites More sharing options...
Yebin Chung Posted May 5, 2012 Report Share Posted May 5, 2012 is this for tz1 or tz2? Link to post Share on other sites More sharing options...
Peanut Butter Jelly Posted May 5, 2012 Report Share Posted May 5, 2012 (edited) I don't know but TZ1 was stupidly difficult. I did a couple practice papers and TZ1's paper were the most difficult. Edited May 5, 2012 by Vol de Mort Link to post Share on other sites More sharing options...
IBsurvivor2012 Posted May 5, 2012 Report Share Posted May 5, 2012 As for two equal roots, i think i got k= 3 & -1too equal roots basically means the same as one answer! so you had to make Delta=0.. which makes k=3that's why "equal" was in bold fontI took two equal roots to mean the discriminant = 0 (b^2 - 4ac) because that gives one repeated root, so there would, technically, be two equal roots. So that would mean that the x values have to be the same, not the k ones - right? Since k is the constant, not the variable.I could be completely wrong here, but that's what I took it to mean and how I approached it. I found that both k = 3 and k = -1 led to one repeated root (they led to (x-1)^2 and (x+1)^2 I think), so I kept both of them in.Hey.. I did the same thing.. So is it correct? Link to post Share on other sites More sharing options...
Outis Posted May 5, 2012 Author Report Share Posted May 5, 2012 Paper 1 in TZ1 wasn't too bad. Question 10 was killer; my teacher hasn't even figured it out yet.My schools in Canada, so i guess that's time zone 1. I thought that Paper 1 was relatively straight forward, other than question 10 of course. That's the one about velocity and distance i believe? although I forgot to simplify my final answer I think I got it reasonably correct. Link to post Share on other sites More sharing options...
007imagine Posted May 5, 2012 Report Share Posted May 5, 2012 (edited) I had TZ1. Yeah. But in all seriousness, it could go either way. I had trouble with 6 and 10. Can't even remember what 6 was about. Reading this thread, I was panicking thinking I bombed the entire test...until I realized these were TZ2 questions. Edited May 5, 2012 by 007imagine Link to post Share on other sites More sharing options...
vids.10 Posted May 5, 2012 Report Share Posted May 5, 2012 haha..this is TZ2... and oh my god, i think this binomial expansion question has screwed everyone's head up...like me.. Hey guys, how was p2? I found section B to be very tough...Did anyone get the last question number 10??????? Link to post Share on other sites More sharing options...
ro_1293x Posted May 5, 2012 Report Share Posted May 5, 2012 The funny thing is I think I did the expansion question differently then everyone and still ended up with the right answer I started out the same way but my final calculation looked different but I think that's because I made it more complicated for myself. And on top of that my paper is a mess because I went in a completely wrong direction at first before realizing I had to cross it all out, so I wonder if they will even be able to read what I have done apart from the giant n = 14 Anyhow even if I lose like 3 marks it's not going to hurt. Usually at least a 80/90 is a 7 right? TZ2 was pretty easy... TZ1 has supposedly been known to be harder Sucks for North America. haha..this is TZ2... and oh my god, i think this binomial expansion question has screwed everyone's head up...like me.. Hey guys, how was p2? I found section B to be very tough...Did anyone get the last question number 10??????? It's not been 24 hours yet... can't discuss paper 2. Link to post Share on other sites More sharing options...
Vincent Casey F Posted May 5, 2012 Report Share Posted May 5, 2012 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 I took two equal roots to mean the discriminant = 0 (b^2 - 4ac) because that gives one repeated root, so there would, technically, be two equal roots. So that would mean that the x values have to be the same, not the k ones - right? Since k is the constant, not the variable. I could be completely wrong here, but that's what I took it to mean and how I approached it. I found that both k = 3 and k = -1 led to one repeated root (they led to (x-1)^2 and (x+1)^2 I think), so I kept both of them in. yeah yeah that's exactly what I meant! you did it right to get a 7 in 2011 you had to be over 80, in 2010 it was 77, and in 2008 it was 67! You can never tell! Link to post Share on other sites More sharing options...
Guest Posted May 5, 2012 Report Share Posted May 5, 2012 yeah yeah that's exactly what I meant! you did it rightOkay, great! I really freaked out for a second thinking I had gone the complete wrong direction! I'm really hoping for a 7 now... P1 and my IAs were good, so hopefully it'll all turn out well! (although I feel like after that P1 the boundaries will be on the high side for TZ2 [at least for that paper] but oh well) Link to post Share on other sites More sharing options...
Beastern Posted May 5, 2012 Report Share Posted May 5, 2012 Yeah, I also believe that the grade boundaries are going to be harsh.. Failed with conditional probabilities in both papers, though. Link to post Share on other sites More sharing options...
uusinjsh Posted May 5, 2012 Report Share Posted May 5, 2012 Great to hear, that k was 3 AND -1.. Hoping for a 7 as well, even though there were some tricky parts in Paper2.. Link to post Share on other sites More sharing options...
HoolaBaloola Posted May 5, 2012 Report Share Posted May 5, 2012 Great to hear, that k was 3 AND -1.. Hoping for a 7 as well, even though there were some tricky parts in Paper2. That's correct , paper 1 wasn't hard at all (i only messed up the arithmetic's on probability, area under graph and binomial, so i could get a -2 on each of those questions) Still hoping for a 7 though. However, I believe it's not good to dwell in this ultimate ego. It could affect our performance on other subjects, so stay sharp! Link to post Share on other sites More sharing options...
uusinjsh Posted May 5, 2012 Report Share Posted May 5, 2012 Don't worry, I won't get complacent as the next exam is Physics, which... well... If I get a 4, I will be lucky Link to post Share on other sites More sharing options...
HoolaBaloola Posted May 5, 2012 Report Share Posted May 5, 2012 Don't worry, I won't get complacent as the next exam is Physics, which... well... If I get a 4, I will be lucky Haha, I'm oh so scared of magnetics. Don't know a single thing about it! Link to post Share on other sites More sharing options...
omri Posted May 5, 2012 Report Share Posted May 5, 2012 So what do you think will be the grade boundaries of this paper? Link to post Share on other sites More sharing options...
candypop Posted May 5, 2012 Report Share Posted May 5, 2012 I got one as 5/11, I think it was c, as for b....I think it was 11/21....not sure though...how did you get 11/21? this is the one with the two white balls from bag A right?? I just multiplied the probabilities of getting white balls along the branches of the tree diagram so I got 3/7 * 2/6 = 1/7not sure if I read the question wrong now, do you remember how many white balls there were in total in bag A? Link to post Share on other sites More sharing options...
kkay Posted May 5, 2012 Report Share Posted May 5, 2012 I got one as 5/11, I think it was c, as for b....I think it was 11/21....not sure though...how did you get 11/21? this is the one with the two white balls from bag A right?? I just multiplied the probabilities of getting white balls along the branches of the tree diagram so I got 3/7 * 2/6 = 1/7not sure if I read the question wrong now, do you remember how many white balls there were in total in bag A?Yeah I got 1/7 too Link to post Share on other sites More sharing options...
vids.10 Posted May 5, 2012 Report Share Posted May 5, 2012 I got one as 5/11, I think it was c, as for b....I think it was 11/21....not sure though...how did you get 11/21? this is the one with the two white balls from bag A right?? I just multiplied the probabilities of getting white balls along the branches of the tree diagram so I got 3/7 * 2/6 = 1/7not sure if I read the question wrong now, do you remember how many white balls there were in total in bag A?Yeah I got 1/7 tooI got one as 5/11, I think it was c, as for b....I think it was 11/21....not sure though...how did you get 11/21? this is the one with the two white balls from bag A right?? I just multiplied the probabilities of getting white balls along the branches of the tree diagram so I got 3/7 * 2/6 = 1/7not sure if I read the question wrong now, do you remember how many white balls there were in total in bag A?Yeah I got 1/7 tooThat's right! even i got that. That's because .. there were total 7 balls, from which 4 were red and 3 white in Bag A. Link to post Share on other sites More sharing options...
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