OCR (Not MEI) Core 2 Discussion Thread 17th May 2013 + Jan 13 Paper and MS

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Ok, so you first are given that there is a GP. Therefore terms of GP:
u1=a
u2=ar
u3=ar^2
u4=ar^3
etc...
You are given that 1st, 2nd and 4th term of GP form AP, so terms of AP:
u1=a
u2=ar
u3=ar^3
You know that u2-u1=u3-u2
You get:
ar-a=ar^3-ar
a(r-1)=a(r^3-r)
a is not equal to 0 so you can divide by a to get:
r-1=r^3-r
r^3-2r+1=0

Hi i don't know if i'm being really stupid, but how do you know that
u2-u1=u3-u2....?

apologies if i am being really stupid haha

Reply 41

pinpin95

exam q. help xD

tan a= 2/5
what is cos a?

i attempted it:

a= tan^-1(2/5)
a= 21.8

cos(21.8)= 0.928

mark scheme says: cos a= 5/√29

can anyone help please?? thnx

its ok i just realised i had the correct answer all along!!!! silly moi :biggrin:

(edited 10 years ago)

Reply 42

purplemind

Original post by nimsay1

Hi i don't know if i'm being really stupid, but how do you know that
u2-u1=u3-u2....?

apologies if i am being really stupid haha

It is an arithmetic progression. The common difference is the same between 3rd and 2nd term, and 2nd and 1 st term?

Reply 43

pinpin95

good luck everyone! we WILL pass!

Reply 44

Substitution

Original post by pinpin95

Answers on page 1 to this,

Reply 45

Jess x

got a good feeling about this exam.. as long as it's not like the jan 2013 paper we should all be fine! good luck everyone :smile:

Reply 46

ChocolateCream3

Mr M, please need you now!! Answers!!

Reply 47

Rrobba

That went pretty badly for me.

Anyone get these:

Area under graph: 2.4
Solutions for cubic: pi, 4/3 pi and 2/3 pi
34cm for perimeter of the shape
62.2cm^2 for area of shape

Reply 48

mia_hilton

Hi guys how did it go?
there were two 5 markers that i couldnt get my head around and a 3 marker that was difficult
but apart from that it was ok (13 marks + are hanging ) hope grade boundaries will be low :smile:

Reply 49

Music99

Original post by Rrobba

That went pretty badly for me.

Anyone get these:

Area under graph: 2.4
Solutions for cubic: pi, 4/3 pi and 2/3 pi
34cm for perimeter of the shape
62.2cm^2 for area of shape

Cant remember the area under curve answer, I got same cubic answers and perimeter. I think my area was the same can't fully remember.

Reply 50

purplemind

I think it was relatively easier than January exam. :smile:

Fine for me.

Original post by Rrobba

That went pretty badly for me.

Anyone get these:

Area under graph: 2.4
Solutions for cubic: pi, 4/3 pi and 2/3 pi
34cm for perimeter of the shape
62.2cm^2 for area of shape

I got 37/30 for area under the curve.
Got the same for cubic, perimeter and area.

(edited 10 years ago)

Reply 51

mia_hilton

Original post by Rrobba

That went pretty badly for me.

Anyone get these:

Area under graph: 2.4
Solutions for cubic: pi, 4/3 pi and 2/3 pi
34cm for perimeter of the shape
62.2cm^2 for area of shape

Considering that i couldnt even do the are under the graph one - i think you've done well !
I think i got similar answers to the last 3 , you'll be fine ! :smile:

Reply 52

lexy0202

I got ~1.23 for area under graph, same solutions for cubic in cos and perimeter.. don't remember are of shape.

Reply 53

Music99

Original post by mia_hilton

Considering that i couldnt even do the are under the graph one - i think you've done well !
I think i got similar answers to the last 3 , you'll be fine ! :smile:

You had to subtract the area of the triangle.

Reply 54

ChocolateCream3

When do you guys think mr m will load the answers up??

Reply 55

mia_hilton

Original post by purplemind

I think it was relatively easier than January exam. :smile:

Fine for me.

I got 37/30 for area under the curve.
Got the same for cubic, perimeter and area.

Well done, best not ask you what you think the grade boundaries will be then :wink:

Reply 56

mia_hilton

Original post by Music99

You had to subtract the area of the triangle.

but how did you know the coordinate of the tangent when it hit the x axis?

Reply 57

purplemind

Original post by mia_hilton

Well done, best not ask you what you think the grade boundaries will be then :wink:

Don't worry. I know many people in my school didn't like the exam either. I just had a lot of practice so I didn't find any questions a surprise. :smile:

Reply 58

sbath94

what did everyone get for 'c' in the binomial question? i got 24, not sure if it's correct