MAY 2010 | MATHS SL (don't know what timezone) AFTER EXAM TALK

[uhm&ahh]

it gave you the function and the graph, you had to find some points on the graph,as well as the derivative. Then it asked to find the x intercept, i got 3pi/2. It then asked to find the area of the shaded region between 0 and 3pi/2. Oh and if i recall the function was f(x)= 6+6sinx. I got an asnwer of 9pi for the area of the shaded region

I also got 9pi on that one so hopefully it's right but did you manage to solve the question after that one? I don't remember the question exactly but you had to plug in some values and find the value of p or something. It was really weird cause in my equation the p's cancelled out each other

[cymbalrush]

How did you solve the equations 6+6 sin x = 0 and 6+6 sin x= 6 that got me very confused. Quite a nasty paper, but I hope I will get the marks for methods e.t.c. and hopefully there have been enough silly people to keep the boundaries low.

[alexno]

it gave you the function and the graph, you had to find some points on the graph,as well as the derivative. Then it asked to find the x intercept, i got 3pi/2. It then asked to find the area of the shaded region between 0 and 3pi/2. Oh and if i recall the function was f(x)= 6+6sinx. I got an asnwer of 9pi for the area of the shaded region

I also got 9pi on that one so hopefully it's right but did you manage to solve the question after that one? I don't remember the question exactly but you had to plug in some values and find the value of p or something. It was really weird cause in my equation the p's cancelled out each other

i think p is pi/2 in that question

[Peachez]

Quite a nasty paper, but I hope I will get the marks for methods e.t.c. and hopefully there have been enough silly people to keep the boundaries low.

Yes, I agree.. I didn't like it much.

Hopefully the grade boundaries will be relatively low.

[alexno]

When is the MS comming out anyone know ?

[uhm&ahh]

Oh well, it was only a 3 point question. If I didn't make too many other silly mistakes I could still get a good grade

[HanoBee]

Paper 1 TZ2 was really hard hopefully not worse than 5 though!

what did you guys get on the log question? I ended up with 4.

Yep i can confirm a 4, wut about question one where we had to find the p p(x-q)(x-r) i got 1/2 for p.

yeah i think i got 1/2 for p as well

[HanoBee]

How did you solve the equations 6+6 sin x = 0 and 6+6 sin x= 6 that got me very confused. Quite a nasty paper, but I hope I will get the marks for methods e.t.c. and hopefully there have been enough silly people to keep the boundaries low.

i thought this one was easy, you just solve for x u'd get 6sinx = -6 then sinx = -1 and sin-1 (-1) = -90 so x is either -90 or 180 +90 depending on the domain given i cnt remember what it was( i think), i got the inverse of -1 wrong anyway so my answer was wrong but i think i'm sure the method's right

for the 6+6sinx=6 it becomes 6sinx=0 and sin-1 (0) =0 so x= 0 or x=180 (which is pi) and again u get x depending on the domain given

the paper was really really hard though i just hope i don't fail it, i'd take a 3

[HanoBee]

yeah, that's correct.. I'm pretty confident about that one! how did you do on the probability question?

I'm pretty sure that the IB made a mistake in that question, and it got me stuck and I lost around 20 minutes (causing me not to have enough time for the exam)...

It said that Jose misses the bus 2/3 times, and 1/3 times he obviously catches it. But then, in that table you had to copy and complete, under 0 euros, it should have been:

(probability of missing the bus) * (probability of missing the bus)

= 2/3 * 2/3

= 4/9

when they put that it was 1/9...

Can anyone confirm this? I'm thinking about going to talk to my teacher...

yeah i was actually confused about this one cuz i didn't know whether the probability was 4/9 or 6/9, i settled for 4/9 because adding the probabilites up in the table gave me a 1 when it was 4/9.

[Teddy_The_Bear]

6+6sinx =0

6sinx = -6

sinx = -1

x = 270 degrees

6+6sinx =6

6sinx = 0

sinx = 0

x = 180 or 360

i got the first one right...the second one i just solved..i hope im right but i rushed it so much during the exam..90mins just aint enuf:(

oh and the log question...I got 3 and -1 but that was cause i didnt change log to log form when i moved it over:(...

Edited May 6, 2010 by Teddy_The_Bear

[91Jacob]

So what did u guys get for the area of the shaded region in the last question? Where you had to express it in terms of pi?

I got 9pi

Same lol, although we both might just be idiots lol. You can never be sure.

[91Jacob]

6+6sinx =0

6sinx = -6

sinx = -1

x = 270 degrees

6+6sinx =6

6sinx = 0

sinx = 0

x = 180 or 360

i got the first one right...the second one i just solved..i hope im right but i rushed it so much during the exam..90mins just aint enuf:(

oh and the log question...I got 3 and -1 but that was cause i didnt change log to log form when i moved it over:(...

Solved this the same way lol.

By the way guys, what's the max points we can get and how many points is 6 usually at?

Edited May 6, 2010 by 91Jacob

[91Jacob]

yeah, that's correct.. I'm pretty confident about that one! how did you do on the probability question?

I'm pretty sure that the IB made a mistake in that question, and it got me stuck and I lost around 20 minutes (causing me not to have enough time for the exam)...

It said that Jose misses the bus 2/3 times, and 1/3 times he obviously catches it. But then, in that table you had to copy and complete, under 0 euros, it should have been:

(probability of missing the bus) * (probability of missing the bus)

= 2/3 * 2/3

= 4/9

when they put that it was 1/9...

Can anyone confirm this? I'm thinking about going to talk to my teacher...

yeah i was actually confused about this one cuz i didn't know whether the probability was 4/9 or 6/9, i settled for 4/9 because adding the probabilites up in the table gave me a 1 when it was 4/9.

Yeah I got the same result I think, but guys how were we supposed to do that point where it went the other way like the probability of him catching the bus provided he was late to school? That one was nuts I left it out.

Btw luiz for future exams, leave whatever is taking you too much time and move on to the next one, it's not worth wasting time for a 2 or 3 point part when you can do another whole exercise.

Edited May 6, 2010 by 91Jacob

[pomoni]

this thread is depressing me hahaha

(discovering many mistakes..........I guess I'm one of the "silly people" who might be the reason the boundaries may be low this year )

but well, life goes on

Edited May 6, 2010 by pomoni

[91Jacob]

this thread is depressing me hahaha

(discovering many mistakes..........I guess I'm one of the "silly people" who might be the reason the boundaries may be low this year )

but well, life goes on

Awesome with the low boundaries thing (I'd love that to happen lol), but don't worry I screwed up a bit too, vote on the poll I'm pretty sure there's a choice for ya .

I messed up the cos2x calculations I just doubled the x instead of using the 1-2sin^2x formula.

Edited May 6, 2010 by 91Jacob

[mimii]

6+6sinx =0

6sinx = -6

sinx = -1

x = 270 degrees

6+6sinx =6

6sinx = 0

sinx = 0

x = 180 or 360

i got the first one right...the second one i just solved..i hope im right but i rushed it so much during the exam..90mins just aint enuf:(

oh and the log question...I got 3 and -1 but that was cause i didnt change log to log form when i moved it over:(...

Solved this the same way lol.

By the way guys, what's the max points we can get and how many points is 6 usually at?

Since you had to give it in pi,

6+6sinx =6

6sinx = 0

sinx = 0

x = 0

x = 2pi

x = pi

6+6sinx =0

6sinx = -6

sinx = -1

x = 3pi/2

and on most practice tests we did in class, the max points was 90. and 6/90 was usually a 1.

Edited May 6, 2010 by mimii

[charlotteee]

I got 9pi too! Nobody else in my class got that, but no one was sure about that question. You guys getting 9pi makes me feel a lot better about myself

The probability table was supposed to be

0 3 6

1/9 4/9 4/9

There was a binomial distribution in that it was 1 2 1 (so 2/9 has to be multiplied by 2).

The expected cost added up to 4 euro's, did you guys get that?

Ahhh and the thing at the end, did you guys get something like (x^3)/2 + (x^2)/2 + (forgot what the coefficient of x was) + 10 ?

[91Jacob]

and on most practice tests we did in class, the max points was 90. and 6/90 was usually a 1.

LOL I mean grade 6 not 6 points.

[pomoni]

The expected cost added up to 4 euro's, did you guys get that?

yupp I got that. But I wrote dollars instead of euros and I was going to kill myself afterwards. Do they take marks off for this?

[Cesc]

The expected cost added up to 4 euro's, did you guys get that?

yupp I got that. But I wrote dollars instead of euros and I was going to kill myself afterwards. Do they take marks off for this?

I doubt that... on the matrices question, did anyone else get the same answer on a and b?