JC 2013 Maths Paper 2 - Mon. June 10th 2013 - OL and HL

Cr4pSnip3r

Bluestrike wrote: »

it means metres squared, since you cant actually do a squared sign, thats what people do

I know that... >.>

I mean where'd the number come from?

Bluestrike

Lost In Confusion wrote: »

flagstones are huge

It said in the question the flagstones were 80 CENTIMETRES by 50 CENTIMETRES, therefore, 5 flagstones wouldnt cover and area of 13 metres by 13 metres / 169 metres squared
If you think about it logically you will understand

Lost In Confusion

Bluestrike wrote: »

It said in the question the flagstones were 80 CENTIMETRES by 50 CENTIMETRES, therefore, 5 flagstones wouldnt cover and area of 13 metres by 13 metres / 169 metres squared
If you think about it logically you will understand

i donno i got 24 but i was using the perimeter

Bluestrike

Cr4pSnip3r wrote: »

I know that... >.>

I mean where'd the number come from?

that was the size of the inside square
x^2 = 5^2 + 12^2
x^2 = 25 + 144
x^2 = 169
x = square root of 169
x = 13

the square is 13 metres squared by 13 metres squared

MomijiHime

But since the last answer was in m you have to change 80cm and 50cm to 0.8 and 0.5 m so when you multiply them it's 1.6 m^2..?

Cr4pSnip3r

Bluestrike wrote: »

It said in the question the flagstones were 80 CENTIMETRES by 50 CENTIMETRES, therefore, 5 flagstones wouldnt cover and area of 13 metres by 13 metres / 169 metres squared
If you think about it logically you will understand

Right, 169m^2.

80cm x 50cm = 4000cm^2. 4000/100 = 40m^2 per flagstone.

169m^2/40m^2 = 4.225.

He can't buy 4.225 flagstones, so he has to buy 5.

MomijiHime

Cr4pSnip3r wrote: »

Right, 169m^2.

80cm x 50cm = 4000cm^2. 4000/100 = 40m^2 per flagstone.

169m^2/40m^2 = 4.225.

He can't buy 4.225 flagstones, so he has to buy 5.

You can't convert cm to m when it's squared. You have to do so beforehand

Cr4pSnip3r

MomijiHime wrote: »

You can't convert cm to m when it's squared. You have to do so beforehand

Hmm, then I'm likely wrong. Bluestrike probably has it right.

Bluestrike

Look at my answer, which I posted earlier. i converted cm to m before

13 m/0.8 m = 16.25 (find how many fitted in length)
13 m/0.5 m = 26 (find how many fitted width)
16.25 x 26 = 422.5 (find area)
422.5 x 20/100 = 84.5 (20% extra)
422.5 + 84.5 = 507
Therefore he needs 507 flagstones

finisher489

http://www.examinations.ie/archive/exampapers/2013/JC003ALP230EV.pdf

IT'S UP ON EXAMINATIONS.IE PEOPLE

Drift_King_33

What did you guys get for the hemisphere and cones question?

ash182

Nearly cried I was so happy with it. Really fell down with P1, think I brought my mark up considerably though ^__^

Lost In Confusion

im pissed off i thought it meant it was only covering the outside of the patio not the inside woops

abcdefghijkl

Does anyone know how many marks that flagstone question was?

greenpyjamas

Was shocked that I could do everything on the Paper, was unhappy with Q12 though. I felt I did much better in this one than Paper 1! Hoping for a B anyways

zubikhan

What was peoples answers for Q1 A,B and C
Thanks

stephlumo

i'm thrilled at how easy i found paper two! i was able to answer everything except i know i got a few questions wrong but sure attempt marks

can anyone remember what they got for the very first question in OL??

Bluestrike

Drift_King_33 wrote: »

What did you guys get for the hemisphere and cones question?

I almost got that right, except i forgot to half my answer after i got sphere volume.
i got 2304 Pi.
it should have been 1152 Pi
then, 1152 Pi - 64 Pi = 1088Pi (cone volume is taken out of hemisphere)
1088 Pi /64Pi = 17 times (i got 35 but hopefully only lose some marks for blunder and usually they will accept your answer from first part)

finisher489

In the triangle ABC, |AB| = 2 and |BC| = 1.
(a) Find |AC|, giving your answer in surd form.
(b) Write cos BAC and hence find BAC .
B
AC
(c) Sketch a right angled isosceles triangle in which the equal sides are 1 unit each and use it to write cos 45 in surd form.
(d) Show that cos 75 ≠ cos 45 + cos 30.

What did you get for this question? Anyone? I haven't done trig since Christmas because I just studied the theorems and hard constructions and took it for granted that I'd remember the basic rules or questions 6 months later

Drift_King_33

Bluestrike wrote: »

I almost got that right, except i forgot to half my answer after i got sphere volume.
i got 2304 Pi.
it should have been 1152 Pi
then, 1152 Pi - 64 Pi = 1088Pi (cone volume is taken out of hemisphere)
1088 Pi /64Pi = 17 times (i got 35 but hopefully only lose some marks for blunder and usually they will accept your answer from first part)

I did the same Will probably get high partial 8 marks

Lost In Confusion

finisher489 wrote: »

In the triangle ABC, |AB| = 2 and |BC| = 1.
(a) Find |AC|, giving your answer in surd form.
(b) Write cos BAC and hence find BAC .
B
AC
(c) Sketch a right angled isosceles triangle in which the equal sides are 1 unit each and use it to write cos 45 in surd form.
(d) Show that cos 75 ≠ cos 45 + cos 30.

What did you get for this question? Anyone? I haven't done trig since Christmas because I just studied the theorems and hard constructions and took it for granted that I'd remember the basic rules or questions 6 months later

theorem of phytagoras basically there...

finisher489

What did you get for this question?

zubikhan

Ok IMO I will do my full analysis of the paper
Q1. A,B,C was easy enough to do but I did not get D. but nothing to complain here, just did not have the skills
Q2. All parts were doable
Q3. Ok here I had a problem, especially with (a) I just wrote random fraction numbers down, I did (b)and (c)
Q4. Again doable
Q5. I won't even comment on this GOBS**T, I wasted my last 20 minutes of the paper trying to go over and over again!!(but hopefully like they did with the 2012 and 2011 project maths paper, reduce the marks substantially, there was a question which was similar to this in 2012 and my teacher told me everyone answered it so bad that it was only 2 marks!!!
Q6.Doable, had troubles with the last 2 but again, no complainings
Q7. Doable
Q8. Doable
Q9. Took a lot of you but in the end I think I got it
Q10.A,B,C doable apart from D(What the hell was that all about ??)
Q11. Doable
Q12. Quite disappointed as co-ordinate geometry is one of my strongest in maths, was going good until D and E, I could have gotten F easily if only I had gotten the corrects answers to D and E( I put something down, I think either for D or E it was - something and something....)
Q13+14 Doable apart from the C, but here I have no complainings
Q15. Again what the heck is this ??

I really wanted a B but upon close inspection I would say I need atleast 200 marks in this paper to get 70 on the dot !!(I could be wrong as paper 1, I might have gotten some right which I believe are wrong, but oh well )

Bluestrike

finisher489 wrote: »

In the triangle ABC, |AB| = 2 and |BC| = 1.
(a) Find |AC|, giving your answer in surd form.
(b) Write cos BAC and hence find BAC .
B
AC
(c) Sketch a right angled isosceles triangle in which the equal sides are 1 unit each and use it to write cos 45 in surd form.
(d) Show that cos 75 ≠ cos 45 + cos 30.

What did you get for this question? Anyone? I haven't done trig since Christmas because I just studied the theorems and hard constructions and took it for granted that I'd remember the basic rules or questions 6 months later

This is what i did, bear in mind this may not be right....

(a) 2^2 = 1^2 + x^2
4 = 1 +x^2
4-1 = x^2
3 = x^2
Square root of 3 = x

(b) Cos angle BAC = adjacent/hypotenuse
Cos angle BAC =Square root of 3/2
Cos-1 (function on calculator) (Square root of 3/2 = 30
Cos BAC = 30 degrees

(c) Draw triangle then
Cos 45 = 1/x
Cos 45 = Square root of 2/2
1/x = Square root of 2/2 (cross multiply)
Square root of 2 times x = 2
Divide both sides by Square root of 2 to find x
x = 2/Square root of 2 = Square root of 2 (do it on calculator)
x = Square root of 2
(I just realised I probably did too much but i had loads of time left so it doesnt matter)

(d) Cos 75 = (Square root of 6 - Square root of 2)/4
Cos 45 = Square root of 2/2
Cos 30 = Square root of 3/2
(square root of 6 - Square root of 2)/4 ≠ (Square root of 2/2) + (Square root of 3/2)

Cr4pSnip3r

Bluestrike wrote: »

This is what i did, bear in mind this may not be right....

(a) 2^2 = 1^2 + x^2
4 = 1 +x^2
4-1 = x^2
3 = x^2
Square root of 3 = x

(b) Cos angle BAC = adjacent/hypotenuse
Cos angle BAC =Square root of 3/2
Cos-1 (function on calculator) (Square root of 3/2 = 30
Cos BAC = 30 degrees

(c) Draw triangle then
Cos 45 = 1/x
Cos 45 = Square root of 2/2
1/x = Square root of 2/2 (cross multiply)
Square root of 2 times x = 2
Divide both sides by Square root of 2 to find x
x = 2/Square root of 2 = Square root of 2 (do it on calculator)
x = Square root of 2
(I just realised I probably did too much but i had loads of time left so it doesnt matter)

(d) Cos 75 = (Square root of 6 - Square root of 2)/4
Cos 45 = Square root of 2/2
Cos 30 = Square root of 3/2
(square root of 6 - Square root of 2)/4 ≠ (Square root of 2/2) + (Square root of 3/2)

I did the same as you.

Leopard_Star

now I wish I hadn't dropped down to OL maths...
well on OL I didn't get Q6 or Q7b or Q9c does anyone know how to do those? i had the tables book but I forgot how to use the formulas -__-

Jack_OLantern

Bluestrike wrote: »

I almost got that right, except i forgot to half my answer after i got sphere volume.
i got 2304 Pi.
it should have been 1152 Pi
then, 1152 Pi - 64 Pi = 1088Pi (cone volume is taken out of hemisphere)
1088 Pi /64Pi = 17 times (i got 35 but hopefully only lose some marks for blunder and usually they will accept your answer from first part)

Damnit! Forgot about the cone! I got 18, how many marks will I lose?

Jack_OLantern

Feeling pretty confident about that test. Couple of things, firstly, what did you guys get as the ratios for the last question? I got 4:1 in both but I think that one of them should have been 8:1.

Also, for that question about mobile phones, I got a decimel. My friends, who are really good at maths, got the same. But it would't make sense to have like .3 of a person! I forget my actual answer... It didn't look right anyways.

I think I might just have scraped an A, but I'm happy with a B.

Bluestrike

Jack_OLantern wrote: »

Damnit! Forgot about the cone! I got 18, how many marks will I lose?

Not alot, maybe you will get 8/10 marks?

zubikhan

abcdefghijkl wrote: »

I got a decimal too, for both the male and female. I rounded them off to the nearest whole number, resulting in my percentage answer having no decimals in it, so I think it was correct to round them off.

It was a disgrace of a question
They should have told us to round off.
I hope they give 8 marks in total for that question, the lower the better
lol:mad::eek: