MAY11 Math SL P2 TZ1

[IBSurvivalNum93]

For the bucket question last part I'm not sure if I got it right but this is what I did:

Find the derivative and set it equal to -0.5 and then solved for t. I got 2 t values, one positive and one negative. The negative one obviously wouldn't work and the question did ask for the SECOND t value so I plugged it back into the equation and found it to be above water, in fact just about near the top as it was coming down.

Also would the probability with more than 10 be done like this on a calculator?

1 - binomcdf(240, 0.05, 10)

Edited May 6, 2011 by IBSurvivalNum93

[ms.s.peverell]

I graphed the derivative + 0.5:

4pi/15cos[t(pi/15)]+ 0.5 (since descending velocity means it is equal to -0.5)

and then I found the zeroes. In one period of 0 to 30, I found 2 t values, 10.5 and 19.4.

I then plugged in 19.4 (the second value) into the position function and found that it was negative, and so below the water.

When I checked with these two values, calc dy/dx of the position function at both of these points is -0.5.

For the binomial distribution question, I was able to do the first 2 parts, but couldn't do the last because our teachers never taught us the binomial distribution function. I showed what I would have done:

1-P(X<=9)= 1 - P(X=9)-P(X=8)...-P(X=0) and because it would take me too long and I was afraid I wouldn't have time to complete the other answers, I left it.

I believe I did the statistics question wrong because apparently it said variance was 9, which means standard deviation was 3. I didn't notice and so just used 9 throughout the question as standard deviation and 20 as the mean. So, essentially, I wouldn't have gotten any of that question right.(SIGH)

[sukh]

So Paper Two

I felt even crappier

There was a sneaky question where they wrote variance I didn’t book it so I probably got the question wrong on like 1 out the however many marks it was

Also for the water wheel question I did it correctly until the derivative set it equal to positive 0.5 and got the t value graphed the original found the height and looked for the same height in the 30s got 10.6 one of the right answers and the second was wrong I know I messed up after the derivative how many marks do you think ill get out of 6, as I did the process correct to an extent and got one of the two right t values??

And then this error was carried forward I got 10.6 as my highest value so they said would it be out of the water and I said yes because it would be for 10.6 how many marks would I get out of 4 for that??

Also there was an integration question my calculator was in degree mode which gave me the wrong answer but my process was correct would that be 1 mark off??

Also the machine b thing how many would it need to produce I forgot that it meant that machine a would not be producing 60 if b is producing more and did

0.87= 0.9x + 0.6 x 0.8

Would I get any marks for it out of 4 or zero? or because I followed through correctly I would get a mark ?????

Worst case scenario 20 marks off??

What do you guys think about the questions I asked and also is my scenario somewhat accurate??

[Camille Durocher]

heh that paper 2 sure was a toughie

[Jackie]

I HATED paper 2. Ugh... I thought Paper 1 was looooads easier.

[sillymissrachel]

I feel...okayish about Paper 2. Definitely not as good as Paper 1, but still all right. I also got like 0.07 on the percent thing...oh, the bucket question. That was tough. I actually liked number ten, though (and think I did pretty well on it). Overall for math I think that I got a seven on Paper 1, a low 7/high 6 on P2, and a pretty solid 6 overall...not that bad, right?

Then again, I really have no idea.

[iMuffinsx3]

I believe I did the statistics question wrong because apparently it said variance was 9, which means standard deviation was 3. I didn't notice and so just used 9 throughout the question as standard deviation and 20 as the mean. So, essentially, I wouldn't have gotten any of that question right.(SIGH)

NOOOOOO!

Are you serious?

I messed up too on the variance question.

I'm praying to high heavens that it gets brushed aside as a mis-read.

[fantalove]

The bucket exam wasn't that hard for me.

I was SOOO lucky to practice 2010 TZ0 (november) paper 2. The questions were almost identical

except it wuz a ferriswheel instead of bucket. Just some difference with the approach.

I think this paper 1 and paper 2 was really easy. The only hard question was graphing for paper 1.

Paper 2 was easier than paper 1.

[IB1011]

Well, for last year to get a 7 on paper 2 you had to get 75+ marks out of 90 marks. Overall for a 7 you need 84 to 100. So it not too hard to achieve lol 75 marks is not that high, but then again I'm sure I got like 70% of paper 2, which btw I thought was much MUCH easier than paper 1!!

[thinkpink]

yupp, it was def inverse.

and also, in the probability/stats question, it was asking about the chance of greater than 10 eggs being brown right?

i believe it said 10 or more, or at least 10, or along those lines. so you minus the range from 0-9... i think it said "at least 10"

[thinkpink]

I graphed the derivative + 0.5:

4pi/15cos[t(pi/15)]+ 0.5 (since descending velocity means it is equal to -0.5)

and then I found the zeroes. In one period of 0 to 30, I found 2 t values, 10.5 and 19.4.

I then plugged in 19.4 (the second value) into the position function and found that it was negative, and so below the water.

When I checked with these two values, calc dy/dx of the position function at both of these points is -0.5.

For the binomial distribution question, I was able to do the first 2 parts, but couldn't do the last because our teachers never taught us the binomial distribution function. I showed what I would have done:

1-P(X<=9)= 1 - P(X=9)-P(X=8)...-P(X=0) and because it would take me too long and I was afraid I wouldn't have time to complete the other answers, I left it.

I believe I did the statistics question wrong because apparently it said variance was 9, which means standard deviation was 3. I didn't notice and so just used 9 throughout the question as standard deviation and 20 as the mean. So, essentially, I wouldn't have gotten any of that question right.(SIGH)

I got the exact same as you for the bucket question! YAY & For binom you have the right gist, you just needed to know how to use binomcdf! but just writing out the method would have definitely got you method marks and yes, the standard deviation was 3. i almost missed that! They still give method marks though, don't worry!

[fantalove]

Going back to the bucket question (stupid bucket!!) since t was supposed to be time, time cant be negative, so would the answer be not underwater because the other value for t gave us a positive number? By the way, how were you supposed to know which value was the second one?

I also thought the second test was much easier than the first test. I was so frustrated on the first test because i to tally forgot E(X)!!! And we had done a similar question the day before as practice!!! Oh well, that one was only two points anyways.

Does anyone know what the score range is to get a 7?

I believe it's usually 75-80/90 for each paper

[jess1ca]

While I was doing the exam, I felt that paper 2 was harder than paper 1... I was working at a slower pace. I had about 45 minutes to check over paper one but only like 15 for paper 2. But looking back I think both were pretty equal. That's my opinion, most of my friends loved paper 2 and did not like paper 1 at all!

The bucket exam wasn't that hard for me.

I was SOOO lucky to practice 2010 TZ0 (november) paper 2. The questions were almost identical

except it wuz a ferriswheel instead of bucket. Just some difference with the approach.

I think this paper 1 and paper 2 was really easy. The only hard question was graphing for paper 1.

Paper 2 was easier than paper 1.

Oh my goodness same here, I'm so glad I did the ferris wheel question! The one on the exam was like an easy version of it.

It was like "SHOW a=4", "show b=pi/15". Actually on both papers they had a lot of those type of questions.

For the standard deviation question, I remember my teacher drilling the whole variance vs SD thing in our heads when we were doing the whole unit. But it was still pretty sneaky of them, in past exams they usually stated the standard deviation, not the variance! At least they didn't put X~N (___, 9), they wrote variance in words.

For binomial distribution, I wrote the formula out but I just calculated it on my GDC.

For the derivative question near the end on paper 2, somehow I found the wrong point of inflection (it was supposed to be 1/4 and -1/4), I think I typed something wrong in my calculator. :( But I sketched a graph and showed my work so I'm really hoping for part marks. Also, for part D, when it said to prove it was a point of inflection, I did show I knew how to do the second derivative test... part marks, hopefully?

Does anyone know how many marks that question was worth??? We took up the exam at school but I didn't pay attention to the number of marks each question was worth, and of course we didn't have a markscheme!

Oh and for the log question with the inverse, if you wrote f'(x)= instead of f^-1(x)=

maybe they'll count it as a misread???

For the bucket question last part I'm not sure if I got it right but this is what I did:

Find the derivative and set it equal to -0.5 and then solved for t. I got 2 t values, one positive and one negative. The negative one obviously wouldn't work and the question did ask for the SECOND t value so I plugged it back into the equation and found it to be above water, in fact just about near the top as it was coming down.

Also would the probability with more than 10 be done like this on a calculator?

1 - binomcdf(240, 0.05, 10)

The correct t values are 10.6 and 19.4, but you probably just made a typo or something so you'll probably get marks for method.

P(X≥10)= 1- binocdf (240, 0.05, 9)

1 - binomcdf(240, 0.05, 10) would be subtracting P(X=10) from the probability but here

P(X≥10)= P(X=10)+ P(X=11)+P(X=12)...+P(X=240)

or P(X≥10)= 1- P(X=9)-P(X=8)...- P(X=0)

Edited May 9, 2011 by SmilingAtLife:)

[Req]

The eggs was surely a binomial distribution question.... @summer glau: I found the ln question really easy since we had a calculator... Where were you stuck?

Only Americans and Canadians here right? (I mean in TZ1)

URUGUAY PRESENT

[khan911]

The bucket wasn't underwater. If it started at y=2 and u got -1 then bucket would be at y=1 which is still above water