***2015 LC Maths Paper 1 - Higher Level - June 5th***

m.xvii

I'm just after realising that I forgot to add in the make and model of my calculator, which is obviously my own fault but the invigilator never mentioned it at the end when he reminded us to put our exam number and center stamp.

DarraghF197

m.xvii wrote: »

I'm just after realising that I forgot to add in the make and model of my calculator, which is obviously my own fault but the invigilator never mentioned it at the end when he reminded us to put our exam number and center stamp.

Ummm, what's a centre stamp?!

Nim said earlier that it doesn't matter, just don't forget to do it in paper two.

cainteach96

m.xvii wrote: »

I'm just after realising that I forgot to add in the make and model of my calculator, which is obviously my own fault but the invigilator never mentioned it at the end when he reminded us to put our exam number and center stamp.

I just realised last night too! Yeah I think we should've been told too! Glad I'm not the only one !

Bah_Humbug

For Q4,I understand now how the answer's 0, but can someone explain why its incorrect so say a=1 r=w n=n-1 and then work it out to be -1/w. I know it's wrong but I don't understand why, and would I get any marks at all d'you think?

Daire234

Bah_Humbug wrote: »

For Q4,I understand now how the answer's 0, but can someone explain why its incorrect so say a=1 r=w n=n-1 and then work it out to be -1/w. I know it's wrong but I don't understand why, and would I get any marks at all d'you think?

Because 1 is at the start of the sequence so n=n instead of n=n-1, so it would be 1(1-w^n) which equals 0

sdio

Bah_Humbug wrote: »

For Q4,I understand now how the answer's 0, but can someone explain why its incorrect so say a=1 r=w n=n-1 and then work it out to be -1/w. I know it's wrong but I don't understand why, and would I get any marks at all d'you think?

It's because there are n terms, including 1 at the beginning.

Dingle123

Has anyone done out answers for the final 3 questions?

Kremin

Dingle123 wrote: »

Has anyone done out answers for the final 3 questions?

I'd do them if my printer was working, but alas, it is not.

ThePadds

Just wondering if anyone can help me out...On I think it was Q8 or Q9 of the HL Maths P1 (The Question about the longest days of the year in regards March) it never stated how you had to do the Questions it said "hence or otherwise" I just subbed in answers Untill I found the longest day of the year which was nearly 17 hours (16.9999) of sunlight and it worked out as the 20th or 21st of June I can't remember which! Anyway I'm just wondering will I get the marks even though I didn't really use the right methods I just used trial and error? Thanks

sdio

ThePadds wrote: »

Just wondering if anyone can help me out...On I think it was Q8 or Q9 of the HL Maths P1 (The Question about the longest days of the year in regards March) it never stated how you had to do the Questions it said "hence or otherwise" I just subbed in answers Untill I found the longest day of the year which was nearly 17 hours (16.9999) of sunlight and it worked out as the 20th or 21st of June I can't remember which! Anyway I'm just wondering will I get the marks even though I didn't really use the right methods I just used trial and error? Thanks

I think you should get the marks, if you got the right answer in the end!

cathalio11

For one question, I wrote 2 full answers, two different methods.

Upon looking here, one of them was completely correct, one was wrong.

Do they examiners have to give full marks?

Luke Armstrong

For Q4 it says write the value for S in its simplest form, why would they not say find the value of S if the answer's zero?

It's still a geometric series if you use a=1 r=w and n=n-1, doesn't it make more sense if the answer's not 0 because of the phrasing of the question?

Kremin

Luke Armstrong wrote: »

For Q4 it says write the value for S in its simplest form, why would they not say find the value of S if the answer's zero?

It's still a geometric series if you use a=1 r=w and n=n-1, doesn't it make more sense if the answer's not 0 because of the phrasing of the question?

but n isn't n-1, there are n terms, not n-1..

Look at it this way.. if we use the Tn equation..
Tn=ar^n-1

if we do it your way, and let a=1 r=w and n=-2
we get..
Tn=1(w^n-2)
We know the first term is 1, right? So lets put n=1 and see what we get...
T1= 1(w^-1)= 1/w

Now lets try n=n instead of n-1

Tn= 1(w^n-1)
Test for n=1

T1=1(W^0)=1

Which is correct....


Also just notice, that w^n-1 is the last term (n=n)... which is what the sequence in the question also was....

So if we take a=1, r=w n=n
We get
Sn= 1(1-w^n)/1-w

w^n=1 so we get 1-1/1-w which is just 0.

aaronlalorf

Pretty sure they do, yeah

Think I got in the region of 94%, and am chuffed ^_^

For that question where you had to prove the coordinates were on the curve, messed up first time and I had to do an extra answer on the back page, and it was extremely long-winded and ended up getting a different y-value. (it was meant to equal 0.0025 or something)..

There was a lot of x-subbing in and I just I wrote at the end y =0.0025 Q.E.D. hahahaha

Kremin

I'll prove it to you another way, let me write this out real quick

Luke Armstrong

I wasn't saying you're wrong just that the way they phrased the question suggests the answer shouldn't be zero

Kremin

Luke Armstrong wrote: »

I wasn't saying you're wrong just that the way they phrased the question suggests the answer shouldn't be zero

Well writing S=0 is expressing in it's simplest form, doesnt get any simpler I dont think?

DarraghF197

cathalio11 wrote: »

For one question, I wrote 2 full answers, two different methods.

Upon looking here, one of them was completely correct, one was wrong.

Do they examiners have to give full marks?

I did the same. Rumour has it that they give you marks for the right answer.

Luke Armstrong

You left out 1/w when going from w^n-1,it shoyld be 1-1/w

Luke Armstrong

nevermind

emma35

finally someone agrees with me that it was 0! I saw a solution elsewhere on line that let the number of terms be n-1 using the sum of geometric series formula and that gave an answer that wasn't zero cant remember what it was but I was like how could that be right cause there are n terms, one of which is 1 so I did it another way in the exam just to be sure like I let a= w and r= r and n= n-1 and then added 0 and still the answer was zero so unless the question was phrased very badly surely the person posting solutions is wrong ..I hope :P

blue_velvet

MmmPancakes wrote: »

Am I the only one who got 88 for the angle of the plane?

I got 88 too!

hannahdfghjkl

Having heart palpitations because I thought my maths went well but now I'm seeing everyone else's solutions and I was wrong lol

oktplz

Anyone know where I can find sample solutions for part B?

Daire234

blue_velvet wrote: »

I got 88 too!

I think it was 2 degrees, you must have taken the angle relative to the y axis instead of the x-axis

ClaireGeraghty

Chef Tony wrote: »

I had 35 for the estimation and 36 for the real. The error I think was something like 2.6, but I could of gotten that bit wrong

got the exact same answer

simplyno1

Anyone able to do out solutions to Q7-Q9? I saw a solution to long bits of Q8, but none for Q9/Q7. Im interested to see the last 2 bits of q7..

spottyapples

So I'm guessing I'm the only one who found the maths paper 1 difficult then.... No ones with me?

Kerrypike

simplyno1 wrote: »

Anyone able to do out solutions to Q7-Q9? I saw a solution to long bits of Q8, but none for Q9/Q7. Im interested to see the last 2 bits of q7..

Where did you see solution for Q8? Thanks

spottyapples wrote: »

So I'm guessing I'm the only one who found the maths paper 1 difficult then.... No ones with me?

You're most definitely not alone :-)

qweerty

spottyapples wrote: »

So I'm guessing I'm the only one who found the maths paper 1 difficult then.... No ones with me?

Most people who still want to talk about an exam the next day are those who will have done well. Also, I would guess that the average score of Boardsies is pretty high. Whatever the difficulty, ~10% of the country will still get an A, ~30% a B, etc.