MAY11 Math SL P2 TZ2

[Ihavequestion]

This paper was okay, but a bit tough. It wasn't hard. Besides, we should have expected a somewhat "tough" paper because the first paper was extremely easy. The last question did indeed prove to be the toughest question in the paper, but this is IB: there is ALWAYS a question that looks new, i.e. has not been asked before, and thus is a bit tough. Cynthia, I wouldn't be surprised if the both of us get the same marks; we both think about questions the same way and have similar answers. As compared to the paper in November 2010, this was way easier. Overall, the whole paper was doable and no one should have had trouble with this. The vectors question was like a generous gift by the IB. This is what they always ask. It's in all papers. Everyone should have got that one right. Can't remember the others... I want to discuss questions you guys want to discuss. Good luck with chemistry on Monday because I know I'm terrified of the HL papers for that day.

hmm, thats a question because some could make silly mistakes which could be missing alot of marks... It was generally very easy but questions like vector if you didnt get the S and T value, then it is difficult to do further although calculation is easy to solve. Anyways, Comparing may 2010, i should say it was almost the same difficulty as this year. So I hope the grade boundaries are same.

[Ihavequestion]

I found paper 2 pretty normal, definitely harder than P1 (TZ2) but I think it went pretty well. Regarding 10, it was definitely the trickiest question in the paper, but still not too hard. Copypaste from FB by someone else on 10c (I did the same thing):

"is that the 7 mark question? i think what u had to do (thats what i did) was first show the graph and show that at x= π/2 (90º) ,which is the boudary they gave in the question, y=4 (show by substituting into the equation), thats when the graph starts having 2 x-values for the same value for y..and then calculate where the max point of the graph is (i got 5.20) and then these are the values for which A has two possible values for theta, so 4≤A<5.20"

The wording was definitely pretty confusing overall.

Just have quick question in paper 2 section A where you are suppose to use binomial theorem given that cofficient of x^2 and find the term

How did you solve them?

[Ihavequestion]

was it like 30% so its 0.3 but there isn't 0.3 so you get 0.7 and then from the tables you get the value of 0.7 but you put a negative sign. then you just put it in the equation and solve?? I hope you understand what i'm saying. i'm talking about the standard deviation question.

By far, what do you guys think about the exam in overall? do you find this exam much easier than one in may 2010 exam?

Because if many thought it was good then overall boundaries will raise.. and that means it is harder to get higher grades.. right?

I just want to know if you think it was as ok as last year. Then it would be still about the same grade boundaries, which you will know already what you will get by now. It seems everyone by far believes to get over 6 to 7. I wish that wasn't the majority's grade cause i dont think i will get that realizing many easy going mistakes i made... tell me what you think about that.

[Cynthia]

Does anyone remember which topics the questions were on from 1-7?

I remember from paper 1 (1. Arithmetic, 2. Probability, 3. Vectors, 4. Derivative, 5. Natural Logarithms, 6. Statistics, 7. Matricies)

What about paper 2 (TZ2) ?

All I can recall immediately is that one of the Paper 2 Section A questions was about the Binomial Theorem.

There was one with matrices where you had to find m and n where MX=N

then you had to solve the equation

I was kind of confused with that matrix question. Was the answer for part (b) and [c] the same? Except for [c] you don't write it in matrix form but as "x,y,z =" form?

Yeah I thought that was what was supposed to be done...

@Ihavequestion; Overall, I think the boundaries may be a bit on the higher side so at least 80 but probably not a lot over that - I found both papers quite easy personally, and the general consensus seems to be that P1 was really easy whereas P2 was more normal.

[Hypnotica]

Guys, for the trapezium question, all you had to do was understand that the graph of whatever the formula was had to intersect the x-axis at two points between the interval 0 and pi/2. If you had that figured out, the rest was easy, it related to the previous question about the area being 5. In quadratic form, the "c" determines where the graph will intersect the x-axis between 0 and pi/2. The answer was -5<c<-4, meaning that the area would lie between 4 and 5. Good luck everyone.

[pete.king]

Guys, for the trapezium question, all you had to do was understand that the graph of whatever the formula was had to intersect the x-axis at two points between the interval 0 and pi/2. If you had that figured out, the rest was easy, it related to the previous question about the area being 5. In quadratic form, the "c" determines where the graph will intersect the x-axis between 0 and pi/2. The answer was -5<c<-4, meaning that the area would lie between 4 and 5. Good luck everyone.

Nah Man the right answer was 4<A<5.2

what did you get for question 7 the calculus one?

[Sharif0721]

You guys, for the last question in paper 2... the one with the trapezium and finding the values for the angle, I just sketched y= 4sin0 + 2sin20 and y= 5 separately and found the intersection point... Would that give me the value of the angle?

[Sharif0721]

And also... Would the grade boundaries change significantly compared to last year? I think that I did really badly in paper 1.. To get a 6 in both papers.. you would need like a 65 to 70 right?

[Naiya]

Guys please tell me how you answered the standard deviation question. Did you do it like how I did? I found the value of 0.7 from the tables then I put it in the equation with a negative value and solved for sigma.

yeah this question....the point you misses out is that the question in a) was to find P(X>27) and we get 0.2 (because 0.5-0.3) obviously!!!

so in part b) we had to find the standard deviation and the way i think i did is right!!

P(X>27)=0.2

P(X<27)= 1-0.2 =0.8 (so see you need not have a negative sign)

then you have P(Z<27-25/sigma)=0.8

so you take the value from the inverse table for 0.8 (which is positive) and solve for sigma and the answer i got was something like 2.38... i dont remember the exact figure...

and yes tell in which equation you substituted? may be that is also another way of doing it...

[Naiya]

Hey... Was the binomial probability answer 0.0508 ??????

yes it is!!

And also... Would the grade boundaries change significantly compared to last year? I think that I did really badly in paper 1.. To get a 6 in both papers.. you would need like a 65 to 70 right?

i got the angles like 71.42 something and 288... but not sure about the 288 angle because when i tried re-substituting it i got the answer in -5m^2 but anyways area can't be negative and also if we try to imagine the kind of window it makes its weird!! so not sure about 288 at all... but hope 71.42 is correct!!

Edited May 7, 2011 by Naiya

[kasandude]

Without a doubt, question 10 is going to be omitted, at least the last part. The way I understood it was that they are asking for values of A, while the previous part of that question stated that they want a different value of A in the first place. I thereby wrote down the possible values for theta which could equal 5. I know this is not what they are looking for, but I spent about 15 minutes on that question and hadn't even done any working seeing as I was so stumped.

Section A was alright. Still a damn slight harder than P1, but manageable. Didn't do the statistics question because we didn't do it in class (crap teacher). I remember the paper being more hectic than P1 as well, and I was really pressed for time in section B, despite having about more than half the exam time left by the time I reached it.

I see this as payback for the P1, which was impossible to do badly on.

[nomez♥]

Seems like everyone found Paper 1 to be easier than Paper 2.

Am I the only person here who thinks Paper 2 was easier (besides that last question)?

Everyone that I spoke to at my school and in other schools here in Abu Dhabi (TZ2) found that Paper 2 was easier.

[Ihavequestion]

Seems like everyone found Paper 1 to be easier than Paper 2.

Am I the only person here who thinks Paper 2 was easier (besides that last question)?

Everyone that I spoke to at my school and in other schools here in Abu Dhabi (TZ2) found that Paper 2 was easier.

Paper 1 seemed more obvious than paper 2. Some questions were easy to make simple mistakes.

[Vega]

About the ferris wheel question..

I did something really odd when answering and I'm wondering if anyone else did the same thing?

What I did to show that the height after some 8 minute was like 90 m or something.

I took the 50 m that is it after 5 minutes and then i constructed a right sided angled triangle with an angle of 3PI/10 or something. And then that x/sin(3pi/10)= 50/sin90 --> x=50sin(3pi/10) soooo then x+50= the height..

I know now that there is a waaay easier way of doing this with help of the table (But during the exam you sometimes blackout a bit ^^)

So, did anybody else did something this odd? And do you think there are still so marks to be gotten for my "oh so odd" answer?

[ThinkPink5]

Are you kidding me!!?? It was insanely easy, piece of cake, my entire school did as if it was a joke, however, even though it was that easy I made a stupid mistake, since I am not very good under pressure, I forgot to sketch the graph... Anyhow, for all of you who wonder how the task (the last one c and d) is solved: you use your GDC, just find the zeroes and that's it! You couldn't possibly do it without it! For part a, just use the formula and simplify it, and that's the whole thing.

ps. I agree that the formulation of the d part was very, very stupid. IB should really work on it.

[ThinkPink5]

About the ferris wheel question..

I did something really odd when answering and I'm wondering if anyone else did the same thing?

What I did to show that the height after some 8 minute was like 90 m or something.

I took the 50 m that is it after 5 minutes and then i constructed a right sided angled triangle with an angle of 3PI/10 or something. And then that x/sin(3pi/10)= 50/sin90 --> x=50sin(3pi/10) soooo then x+50= the height..

I know now that there is a waaay easier way of doing this with help of the table (But during the exam you sometimes blackout a bit ^^)

So, did anybody else did something this odd? And do you think there are still so marks to be gotten for my "oh so odd" answer?

I also had the same blackout problem and I also tried to do something with the triangle, but I don't think I did it right. Hopefully SOME points are awarded for it. Oh and the right way is like 655697708509748748709848704874 times easier. But, oh well...

[lighthuntz0r]

Guys, for the trapezium question, all you had to do was understand that the graph of whatever the formula was had to intersect the x-axis at two points between the interval 0 and pi/2. If you had that figured out, the rest was easy, it related to the previous question about the area being 5. In quadratic form, the "c" determines where the graph will intersect the x-axis between 0 and pi/2. The answer was -5<c<-4, meaning that the area would lie between 4 and 5. Good luck everyone.

Nah Man the right answer was 4<A<5.2

what did you get for question 7 the calculus one?

I also got 4<A<5.2, I think it's right. Basically, f(pi/2)< angle < maximum. However, "4<A<5.2" is all I wrote on the paper (just used the GDC). I don't know how many N points I can get (out of SEVEN!?) for no working.

For calculus question, c was 3. I don't remember the rest.

[lighthuntz0r]

About the ferris wheel question..

I did something really odd when answering and I'm wondering if anyone else did the same thing?

What I did to show that the height after some 8 minute was like 90 m or something.

I took the 50 m that is it after 5 minutes and then i constructed a right sided angled triangle with an angle of 3PI/10 or something. And then that x/sin(3pi/10)= 50/sin90 --> x=50sin(3pi/10) soooo then x+50= the height..

I know now that there is a waaay easier way of doing this with help of the table (But during the exam you sometimes blackout a bit ^^)

So, did anybody else did something this odd? And do you think there are still so marks to be gotten for my "oh so odd" answer?

For that one I just did f(8) = f(10) - f(2). All points?

[FastMouseP]

Mine went quite well. Not taking into account the fact that our school 'forgot' to photocopy the normal distribution tables! Ah well. Life goes on. =)

[Cynthia]

About the ferris wheel question..

I did something really odd when answering and I'm wondering if anyone else did the same thing?

What I did to show that the height after some 8 minute was like 90 m or something.

I took the 50 m that is it after 5 minutes and then i constructed a right sided angled triangle with an angle of 3PI/10 or something. And then that x/sin(3pi/10)= 50/sin90 --> x=50sin(3pi/10) soooo then x+50= the height..

I know now that there is a waaay easier way of doing this with help of the table (But during the exam you sometimes blackout a bit ^^)

So, did anybody else did something this odd? And do you think there are still so marks to be gotten for my "oh so odd" answer?

For that one I just did f(8) = f(10) - f(2). All points?

Did the same thing because it was the only thing I figured out how to do with the information on the table... it could be full marks, hard to say.