MAY11 Math SL P1 TZ1

[Proletariat]

Mere speculation without the answer key of course, but likely those mistakes would only be a mark off each.

Because most questions have multiple components, I believe the IB Markers are instructed to grade an answer that contains a mistake carried over from a previous question as if the answer given had been the correct one; in other words, they grade the process.

[jess1ca]

I just used the info they gave about the derivative to sketch the graph and labeled one point of inflection at pi/4...

So yeah, the shape was kind of like the graph of y=x^3, like suhk said.

It's just a sketch so according to my teacher, it didn't need a scale. I don't think they expected us to actually know what the function looked like, only understand that the graph is increasing when dv/dt>0. So I wouldn't worry if you didn't know how to scale it or if it wasn't exact!

I never thought about actually drawing the distance-time graph, I was too lazy to integrate the function. I just wrote an integral expression and shaded the area under the velocity curve. If they want it on the same graph, doesn't it mean they want you to shade the area? It wouldn't make sense to draw the displacement function on a graph with axes labeled velocity over time!

As for the question about the range of k, I put p is equal to or greater than zero. Since it's opening up and touches the x axis.

Wow I'm surprised I remember all my answers. I want to stop thinking about the exam but I can't. I want that seven!!

I think I might have found the exam easy because I did a lot of November exams. Also, at my school we got a month of exam review. Although I didn't start cramming practise exams until the last week.

All the May questions seem to be easier versions of the November ones... Is there a reason for that? Are all the smart kids in the southern hemisphere?

Edited May 6, 2011 by SmilingAtLife:)

[sukh]

SO Paper one for the Math Exam

First of all, when I walked out I felt SUPER crappy

The last velocity and accelerations question was dam hard I forgot to add in the domain as they stated and they said either “sketch” or show one of them for the displacement function and some people shaded it while I drew the line for the displacement function I am not sure who is correct

Also for the vectors question they asked to find cos x and I didn’t simplify and added wrong= which carried forward to find the sin x I don’t know if ill get the marks and I also had the sin x equal a positive and negative as it did not have a given domain while some people only got sin x positive. Also, for the value of ‘p’ I got greater than or equal to zero some people said that they sated p could not equal zero so mark taken off there maybe

There was also a trig equation to solve I got 6 answers I don’t remember if they were repeated but if so then I am ok as other people I have to talked to got only 3 answers pie/2, 3pie/2, 5pie/2

So I am also not sure about that question

Overall worst case scenario I might have gotten 20 marks off

what do you guys think about my mistakes and let me know what you got for those questions as i am not really sure

and is my worst case scenario correct??

[jess1ca]

sukh I replied to you in my above post. I'm pretty sure p can equal zero. It's a parabola that crosses the x axis, so y equals zero on a point on the graph. So I think you are right. Everyone I know put p is greater or equal to zero.

For the trig question I only got 2 answers! pi/2 and 5pi/2. If I recall correctly, it simplified to sin x= 1. I don't really understand, because sin 3pi/2 =/=1. But I'm not sure about that one because half my friends got 2 solutions and others got 3 though.

There's no way you could have lost 20 marks with what you put above! In my practise exams I messed up 1/3 of the questions and I only lost like 5 marks. You get marks for method and follow through marks too, so I really wouldn't worry. Don't feel bad! Celebrate because math exams are over!!

(At my school though we still have a ton of math left to learn-- yay!)

Edited May 6, 2011 by SmilingAtLife:)

[sukh]

sukh I replied to you in my above post. I'm pretty sure p can equal zero. It's a parabola that crosses the x axis, so y equals zero on a point on the graph. So I think you are right. Everyone I know put p is greater or equal to zero.

For the trig question I only got 2 answers! pi/2 and 5pi/2. If I recall correctly, it simplified to sin x= 1. I don't really understand, because sin 3pi/2 =/=1. But I'm not sure about that one because half my friends got 2 solutions and others got 3 though.

There's no way you could have lost 20 marks with what you put above! In my practise exams I messed up 1/3 of the questions and I only lost like 5 marks. You get marks for method and follow through marks too, so I really wouldn't worry. Don't feel bad! Celebrate because math exams are over!!

(At my school though we still have a ton of math left to learn-- yay!)

but for the trig it had cos x = something and sin x= something so i got 3 answers for each my answers might have been repetitive as i forgot to put them together and also if i had extra answers does that mean they will take off marks??

[sukh]

I just used the info they gave about the derivative to sketch the graph and labeled one point of inflection at pi/4...

So yeah, the shape was kind of like the graph of y=x^3, like suhk said.

It's just a sketch so according to my teacher, it didn't need a scale. I don't think they expected us to actually know what the function looked like, only understand that the graph is increasing when dv/dt>0. So I wouldn't worry if you didn't know how to scale it or if it wasn't exact!

I never thought about actually drawing the distance-time graph, I was too lazy to integrate the function. I just wrote an integral expression and shaded the area under the velocity curve. If they want it on the same graph, doesn't it mean they want you to shade the area? It wouldn't make sense to draw the displacement function on a graph with axes labeled velocity over time!

As for the question about the range of k, I put p is equal to or greater than zero. Since it's opening up and touches the x axis.

Wow I'm surprised I remember all my answers. I want to stop thinking about the exam but I can't. I want that seven!!

I think I might have found the exam easy because I did a lot of November exams. Also, at my school we got a month of exam review. Although I didn't start cramming practice exams until the last week.

All the May questions seem to be easier versions of the November ones... Is there a reason for that? Are all the smart kids in the southern hemisphere?

i get what you mean about not being able to draw a displacement graph on a velocity and time axis but doesn't it make sense as they said to sketch on the graph so i did

i know many people shaded it in but i know some who drew a line too so doesnt it make sense or not at all (be thruthful)

i wont feel more crappier

[jess1ca]

sukh I replied to you in my above post. I'm pretty sure p can equal zero. It's a parabola that crosses the x axis, so y equals zero on a point on the graph. So I think you are right. Everyone I know put p is greater or equal to zero.

For the trig question I only got 2 answers! pi/2 and 5pi/2. If I recall correctly, it simplified to sin x= 1. I don't really understand, because sin 3pi/2 =/=1. But I'm not sure about that one because half my friends got 2 solutions and others got 3 though.

There's no way you could have lost 20 marks with what you put above! In my practise exams I messed up 1/3 of the questions and I only lost like 5 marks. You get marks for method and follow through marks too, so I really wouldn't worry. Don't feel bad! Celebrate because math exams are over!!

(At my school though we still have a ton of math left to learn-- yay!)

but for the trig it had cos x = something and sin x= something so i got 3 answers for each my answers might have been repetitive as i forgot to put them together and also if i had extra answers does that mean they will take off marks??

Ok actually I'm trying to remember and I think the problem was 2cosx= sin2x

Here's how I solved it:

2cosx/cosx=2sinxcosx/cosx

2=2sinx

sinx=1

x= pi/2, 5pi/2

I don't know, that could be wrong. Could someone check it?

EDIT: figured it out. Forgot about finding when cosx=0. !!

For me in my mind right now, all my answers are correct unless proven wrong. I can live with an 89/90, until July, when I find out my (much lower) real mark.

From the old markschemes, usually you get 1 mark per correct answer, and you lose 1 mark for extra answers. If it was repetitive, I'm not sure. I don't know, I'm a student just like you, who just wrote the exam.

Edited May 6, 2011 by SmilingAtLife:)

[sukh]

sukh I replied to you in my above post. I'm pretty sure p can equal zero. It's a parabola that crosses the x axis, so y equals zero on a point on the graph. So I think you are right. Everyone I know put p is greater or equal to zero.

For the trig question I only got 2 answers! pi/2 and 5pi/2. If I recall correctly, it simplified to sin x= 1. I don't really understand, because sin 3pi/2 =/=1. But I'm not sure about that one because half my friends got 2 solutions and others got 3 though.

There's no way you could have lost 20 marks with what you put above! In my practise exams I messed up 1/3 of the questions and I only lost like 5 marks. You get marks for method and follow through marks too, so I really wouldn't worry. Don't feel bad! Celebrate because math exams are over!!

(At my school though we still have a ton of math left to learn-- yay!)

but for the trig it had cos x = something and sin x= something so i got 3 answers for each my answers might have been repetitive as i forgot to put them together and also if i had extra answers does that mean they will take off marks??

Ok actually I'm trying to remember and I think the problem was 2cosx= sin2x

Here's how I solved it:

2cosx/cosx=2sinxcosx/cosx

2=2sinx

sinx=1

x= pi/2, 5pi/2

I don't know, that could be wrong. Could someone check it?

For me in my mind right now, all my answers are correct unless proven wrong. I can live with an 89/90, until July, when I find out my (much lower) real mark.

From the old markschemes, usually you get 1 mark per correct answer, and you lose 1 mark for extra answers. If it was repetitive, I'm not sure. I don't know, I'm a student just like you, who just wrote the exam.

sin2x is a double angle formula and umm you are not supposed to divide by cos x because you will get rid of a solution

hopefully that helps or i can do it for you

Edited May 6, 2011 by sukh

[jess1ca]

i get what you mean about not being able to draw a displacement graph on a velocity and time axis but doesn't it make sense as they said to sketch on the graph so i did

i know many people shaded it in but i know some who drew a line too so doesnt it make sense or not at all (be thruthful)

i wont feel more crappier

What I say doesn't matter, only IB has the real answer But wasn't that part only out of 1? or 2?

I know some people who drew a line for the VELOCITY function. And then shaded the area under that. Now that doesn't make sense. Don't worry about it...

The reason why I'm curious about the exam is because I still have more math to go. I have a whole unit of math left to learn after exams! And then I'm taking data management next year! Plus I kind of like math now

EDIT again

Oh I get what I'm doing wrong! Wow I'm confusing myself.

I need to find solutions for

2cos=2sinxcosx

2=2sinx

So there would be 3 solutions: pi/2, 3pi/2, and 5pi/2

I don't think it would matter if you repeated them, on my exam for every question I made a therefore statement so that the examiner could clearly see my final answer.

Edited May 6, 2011 by SmilingAtLife:)

[ms.s.peverell]

I just used the info they gave about the derivative to sketch the graph and labeled one point of inflection at pi/4...

So yeah, the shape was kind of like the graph of y=x^3, like suhk said.

It's just a sketch so according to my teacher, it didn't need a scale. I don't think they expected us to actually know what the function looked like, only understand that the graph is increasing when dv/dt>0. So I wouldn't worry if you didn't know how to scale it or if it wasn't exact!

I never thought about actually drawing the distance-time graph, I was too lazy to integrate the function. I just wrote an integral expression and shaded the area under the velocity curve. If they want it on the same graph, doesn't it mean they want you to shade the area? It wouldn't make sense to draw the displacement function on a graph with axes labeled velocity over time!

As for the question about the range of k, I put p is equal to or greater than zero. Since it's opening up and touches the x axis.

Wow I'm surprised I remember all my answers. I want to stop thinking about the exam but I can't. I want that seven!!

I think I might have found the exam easy because I did a lot of November exams. Also, at my school we got a month of exam review. Although I didn't start cramming practise exams until the last week.

All the May questions seem to be easier versions of the November ones... Is there a reason for that? Are all the smart kids in the southern hemisphere?

I see what you mean about the y-axis being for velocity. Luckily, I shaded the area and expressed displacement as an integral. I just think that you have to get some credit for expressing it as a function...

My teacher always had us add scales to our sketches of graphs, so I tried to do what I was taught.

I did make it a constantly increasing function, though because I saw what they said about the derivative increasing despite being 0, but I still worry that I didn't do enough for the sketch.

My friends who don't like math always tell me to forget about the exam and want to move on, but I never can. I keep thinking about all the questions and where I could have gone wrong!

My school started reviewing a month before as well. I had almost all the practice exams they gave us done 2 weeks ago. I figured I would get them done and worry about other subjects.

As for 2cosx=sin2x, I got 5pi/2 and pi/2 as well, but I didn't add 3pi/2- but if you graph them on your GDC, they do intersect at 3 points. I think it's the fact that I eliminated the cosx function by using the double angle identity and dividing it out, and so its properties aren't factored in for that last 3pi/2 answer.

Edited May 6, 2011 by ms.s.peverell

[sukh]

i get what you mean about not being able to draw a displacement graph on a velocity and time axis but doesn't it make sense as they said to sketch on the graph so i did

i know many people shaded it in but i know some who drew a line too so doesnt it make sense or not at all (be thruthful)

i wont feel more crappier

What I say doesn't matter, only IB has the real answer But wasn't that part only out of 1? or 2?

I know some people who drew a line for the VELOCITY function. And then shaded the area under that. Now that doesn't make sense. Don't worry about it...

The reason why I'm curious about the exam is because I still have more math to go. I have a whole unit of math left to learn after exams! And then I'm taking data management next year! Plus I kind of like math now

EDIT

Yeah I did do the double angle formula. See:

2 cosx=sin2x

2cosx=2sinxcosx

2cosx/cosx=2sinxcosx/cosx

2=2sinx

2/2=sin x

sinx=1

x= pi/2, 5pi/2

But since other people got different answers, I just want to know if my thinking is correct. Or did I do something wrong there?

i have math to do too the regular cirriculum which we didnt cover

i dont know what you mean by the drawing velocity and shading under that because what would you shade under if you didnt have the velocity graph

and it kinda said on the same graph sketch/ show the d(t)

and the domain for trig was 3pie i think you only did it up to 2pie

[sukh]

SO Paper one for the Math Exam

First of all, when I walked out I felt SUPER crappy

The last velocity and accelerations question was dam hard I forgot to add in the domain as they stated and they said either “sketch” or show one of them for the displacement function and some people shaded it while I drew the line for the displacement function I am not sure who is correct

Also for the vectors question they asked to find cos x and I didn’t simplify and added wrong= which carried forward to find the sin x I don’t know if ill get the marks and I also had the sin x equal a positive and negative as it did not have a given domain while some people only got sin x positive. Also, for the value of ‘p’ I got greater than or equal to zero some people said that they sated p could not equal zero so mark taken off there maybe

There was also a trig equation to solve I got 6 answers which were repeated but if so then I am ok as other people I have to talked to got only 3 answers pie/2, 3pie/2, 5pie/2

So I am also not sure about that question

are these the right answers? domain was 3pie

Overall worst case scenario I might have gotten 20 marks off

what do you guys think about my mistakes and let me know what you got for those questions as i am not really sure

and is my worst case scenario correct??

so what do other people think about my situation

Edited May 6, 2011 by sukh

[jess1ca]

See my reply above. I did it on paper again, I'm positive there's 3 solutions. I made a mistake the first time.

It helps to draw a diagram. I have a feeling you probably did it right... if you had repeated answers:

2 cos x=2sinxcosx

x= pi/2 3pi/2 5pi/2

2cosx/cosx=2sinxcosx/cosx

2=2sinx

x=pi/2, 5pi/2

But really, don't feel so bad! You can't change your exam answers anyway. Relax, study for your other exams if you have any... and wait till July when you find out that you got that seven

Edited May 6, 2011 by SmilingAtLife:)

[ms.s.peverell]

i have math to do too the regular cirriculum which we didnt cover

i dont know what you mean by the drawing velocity and shading under that because what would you shade under if you didnt have the velocity graph

and it kinda said on the same graph sketch/ show the d(t)

and the domain for trig was 3pie i think you only did it up to 2pie

If you didn't have the velocity graph from part C, it probably would have been acceptable to take your best guess so that you would have something to shade in. I believe the wording was "represent the displacement from 0 to 1 on your graph"

[jess1ca]

I just used the info they gave about the derivative to sketch the graph and labeled one point of inflection at pi/4...

So yeah, the shape was kind of like the graph of y=x^3, like suhk said.

It's just a sketch so according to my teacher, it didn't need a scale. I don't think they expected us to actually know what the function looked like, only understand that the graph is increasing when dv/dt>0. So I wouldn't worry if you didn't know how to scale it or if it wasn't exact!

I never thought about actually drawing the distance-time graph, I was too lazy to integrate the function. I just wrote an integral expression and shaded the area under the velocity curve. If they want it on the same graph, doesn't it mean they want you to shade the area? It wouldn't make sense to draw the displacement function on a graph with axes labeled velocity over time!

As for the question about the range of k, I put p is equal to or greater than zero. Since it's opening up and touches the x axis.

Wow I'm surprised I remember all my answers. I want to stop thinking about the exam but I can't. I want that seven!!

I think I might have found the exam easy because I did a lot of November exams. Also, at my school we got a month of exam review. Although I didn't start cramming practise exams until the last week.

All the May questions seem to be easier versions of the November ones... Is there a reason for that? Are all the smart kids in the southern hemisphere?

I see what you mean about the y-axis being for velocity. Luckily, I shaded the area and expressed displacement as an integral. I just think that you have to get some credit for expressing it as a function...

My teacher always had us add scales to our sketches of graphs, so I tried to do what I was taught.

I did make it a constantly increasing function, though because I saw what they said about the derivative increasing despite being 0, but I still worry that I didn't do enough for the sketch.

I got that when the derivative =0, there's a stationary point of inflection. Otherwise, it's always increasing. Is that what you mean?

I've looked over the markschemes for previous exams, for sketches it's ok if you label points, unless they give you a scale or a diagram to draw your graph on.

I'm more worried about my graph getting smudged/ not scanned properly. I used pencil for the graphs.

[sillymissrachel]

I hate thinking about exams right after taking them, so I might go back and read through all of the comments later...

I thought that it was pretty easy overall...or at least comparable to the previous exams (I probably took a total of seven or eight paper 1 practices). Question 10, though...that one was frustrating, and I'm pretty sure I missed some points. Overall I'm thinking that I probably missed somewhere between eight and twelve points total, which I'm really happy with. But I'm not sure if I ended up making any stupid mistakes. So we will see this summer!

[Phil2154]

I am really glad you all write it "pi" and I write it "π"!!! Anyway... I think paper 1 was difficult for me since I hadn't studied enough but I solved the vector exercise! Does anyone remember? It was asking for the magnitude of a vector and then for the sine of this magnitude... I found -1/3... totally wrong? Thanks!

[alex_b]

ok so i really have a problem and i was wondering if anyone could help mee

soo i am pretty sure that i got a 2 in paper 1 (yes i know it was actually really easy, but i really messed that up)

paper 2 went a bit better im sure that i passed that with a 3 and maaaaybe even a 4

on my internals i got 24/40 which is also pretty bad.. i think it is still a 4 though :/

so heres my question.. think its a realistic though that i will pass math with a 3? :/

[sukh]

ok so i really have a problem and i was wondering if anyone could help mee

soo i am pretty sure that i got a 2 in paper 1 (yes i know it was actually really easy, but i really messed that up)

paper 2 went a bit better im sure that i passed that with a 3 and maaaaybe even a 4

on my internals i got 24/40 which is also pretty bad.. i think it is still a 4 though :/

so heres my question.. think its a realistic though that i will pass math with a 3? :/

yes i think so because they give you many marks for instance if they said find the detrminant of A and you wotr

det(A) you get a mark as it dicussed on the study guide

you may even be able to get a 4

and dont worry you can redo the exam next year - well as far i know

i dont know how your school works

dont worry!!!! wait until JULY 6

[autobahn]

i don't think you were expected to graph in question 10 perfectly, but you did have to piece together pieces of information, such as the y-intercept and the point of inflection.. the shape ended up looking like a weird cubic function, which was confirmed when i graphed it afterwards on my gdc