NOV11 Maths SL P2

[katiep]

How did you find the Maths P2?

Especially that last question on the Ferris wheel- I thought that was the trickiest question on the paper. I ended up finding that the height after 6 mins (Q) was something like 36 meters... wondering how you went about it/if you go the same thing?

But I did think paper 1 was more straightforward than this paper. Thoughts?

Edited November 6, 2010 by katiep

[laryxle]

I don't really know how to feel about it actually. For me, apart from the ferris wheel question and the vector question (gah for some reason I suck at vectors ) it was a really straightforward exam. I don't think I did very well on the ferris wheel question, the height at Q I got was 41m. My working on that bit was pretty dodgy, because I had no idea how to work it out...I used speed=distance/time to find out how fast the wheel was travelling, then said for 6 minutes (360 seconds), x/360=1/9 or something like that and I got x=40, then plus one because the starting point is already 1 metre off the ground. For the last part I got t=12.7 and I didn't round it up to 13 minutes, although i'm not even sure if that was right, I think might have made a stupid mistake in the working for that part.

The thing I noticed was that there seemed to be a lot more questions involving simultaneous equations than in any other paper I had ever done, which probably isn't true, that's just how it felt I (stupidly) did the question on finding p, q and r the very long manual simultaneous equation way that took forever, so I was rushed in section B a little, but at least I know I got that right.

I think I did better on P1 than on P2, and if I had to rate it with the May papers it was definitely harder than TZ2 (although that's not really saying much) and a bit harder than TZ1.

I am thankful that there were no questions of normal distributions in probability, I much prefer binomial distributions

Also I thought it was weird how there were no binomial theorem questions in either papers, and no simple matrices questions in either papers when most papers usually have at least one.

Edited November 6, 2010 by laryxle

[Holy Moly]

I thought Paper 2 was fine, much better than Paper 1 (and I think almost my entire class agrees).

I loved the Ferris Wheel question as I did the ferris wheel question from the November 2007 paper the previous night and there were some similarities.

I ran out of time to finish some parts of the paper though.

Also for that 3 simultaneous question one, I decided that because there were 3 marks you would get 1 mark for each right answer. So I wrote down the values straight of the calculator. I wasn't quite sure how to do a 3 way simultaneous.

Edited November 6, 2010 by Holy Moly

[lynyrd]

I found Paper 2 a little bit more challenging that paper 1. The ferris wheel was the most challenging exercise in the paper, I just got the height at 15 minutes which was 101 m right?

The other section B exercises were not hard. In exercise 9 who did you find to have more probability of passing the exam? Mark or Bill? I went for Bill because he had a little more probability than Mark. (I guess)

What did you get for the standard deviation, median, and IQR in exercise 1? I found that exercise pretty hard, but then they told me that you could do it with the GDC! damn!

Anyway I expect more than 50 points for each paper!

[Albert]

Ok I'm quite confused. It seems some of you thought that the 6 minute ferris wheel question was difficult. If the wheel reaches 101m after 15 minutes (and 15/6 = 2.5) wouldn't you just divide 100 by 2.5 and then add 1? Thus it equals 41m (like laryxle said)? By the way, I got t = 12.8 minutes and forgot to round up to 13 too (I got 12.8 because I used more than 3 significant figures for the calculations and rounded at the end).

Anyways... the last part of number 9 was quite hard. I ran out of time so I took a stab at Bill (hopefully I'll get 1/3 for that!). Question #1 you just had to plug all of the data into a table and do the 1-Var Stats L1,L2 to get the median/SD/interquartile range. And I also found that vectors question quite hard; I got an answer of 18.8 for k! (or 18.7, can't remember which). Overall, however, I did find the paper quite fair and I think I'll end up with a 6. The grade boundary for a 7 is sooo high!

I made a stupid mistake with the Bill/Mark question. I forgot to type one figure into the frickin calculator and I got a negative answer! Can't believe it... hopefully I only lose one mark though!

[markrog]

Im not sure you can find the hight after 6 mins by your method becuase you would have to assume the the increase in high is dependent on the increase in size. Since it is a circle the increases at diffrent time would change depending on the intensity of the angle/curb. Dont take my word for it, its just what I think is logical but then when has logic and math ever fit in together? Personally I found the paper to be alot easier then paper 1 (which I am not confident at all about). The only question I know I messed up on was the probability one becuase I tried to use the mean equation and make it equal 1 to find a and b. (By using simultatious equations and the given equation) I hoped to find A and B, but each time the ended up as the same value. So obviously I was not doing the right thing their. Oh well. I found the ferris wheel question slightly diffcult only becuase I only had like 10 minutes to do it! Atleast math is over, now I can focus on chem (oh joy)

[ridiculous]

Our entire class found paper 2 pretty difficult...most of us found paper 1 easier than we were expecting though so hopefully that balances things out.

Agreed, the absence of binomials and simple matrices Q's was a little disturbing. I remember in Paper 2 looking through the paper praying I had missed a page cos I knew I could get easy marks from those questions Also as far as I can remember there weren't any basic logarithm questions in the papers either...

The ferris wheel one was pretty difficult. For the 6 minutes question I did some weird equating thing with degrees (e.g basically said one revolution = 30 minutes = 360 degrees, and so associated the time with degrees and then used a right angle triangle to find the height). I think I spent too much time gaping at every question so i missed quite a bit of the paper...including most of the probability Q in section B which probably would have given me easy marks...

Oh well, thank god its over. I think I'm guaranteed a 5 though cos I did well in my IAs.

[laryxle]

I think I also screwed up the last part of question 9, I didn't really know what to do so I found the binomial probability of the second guy (can't remember if it was bill or mark) for passing the test (3 or more correct) and it was way lower than the probability for the first guy, so I said that the first guy was more likely, but I wondered if we were supposed to just use E(X). Although, how could that question be worth 3 marks then when both of the guys E(X) was found in previous questions?

I got 8.91 or something like that for the vectors, which made no sense because when I substituted it into my working to check if it was correct, it wasn't Hopefully method marks?

Also keep in mind that whilst the May 2010 7 boundary was 75-77/90 (I think) for P2, for May 2009 it was 68/90, so it fluctuates a LOT, and our paper was definitely harder than TZ2 May 2010 which was the easiest SL maths paper I have ever seen.

[ridiculous]

Do they change the grade boundaries just for the papers, or would they also change the boundaries for the overall subject mark depending on the difficulty of the paper?

[laryxle]

well for M09 it was 79/100 overall for a 7 and for M10 85/100 so I guess so

[Albert]

I think I also screwed up the last part of question 9, I didn't really know what to do so I found the binomial probability of the second guy (can't remember if it was bill or mark) for passing the test (3 or more correct) and it was way lower than the probability for the first guy, so I said that the first guy was more likely, but I wondered if we were supposed to just use E(X). Although, how could that question be worth 3 marks then when both of the guys E(X) was found in previous questions?

I got 8.91 or something like that for the vectors, which made no sense because when I substituted it into my working to check if it was correct, it wasn't Hopefully method marks?

Also keep in mind that whilst the May 2010 7 boundary was 75-77/90 (I think) for P2, for May 2009 it was 68/90, so it fluctuates a LOT, and our paper was definitely harder than TZ2 May 2010 which was the easiest SL maths paper I have ever seen.

I agree with you... I think there was something more to it than using the E(X)'s for Q9. After all, both of the E(X)'s were 1 if I recall correctly!

And in regards to the vectors question; I eventually used trial/error to find the answer to the vectors question and fortunantely for me my answer correlated with the best maths kid at our school!

English, Eco and Chem this week!