OCR MEI C1 20th May

How did you all find it?

I revised heavily for this exam did every practice paper until i was getting at least 90% on each of them, and after comming back from that exam i feel cheated.

So hard in comparison to the practice papers!!!

Just hope C2 is better.

Reply 1

Mr Nonsense

13

wasn't as pi$s easy as the past papers, no

Reply 2

chemcat

I thought it was ok. But lots found it hard. I missed the bit about stating the y-intercept when it was translated by 3 across. Just didn't see it. Did the rest of that part but missed that totally.

The only "hard" question was the n^3-n one where you had to prove it was even for any integer. I just subbed in 2k to show it was even for even numbers and 2k+1 to show for odds. They both were divisible by 2, so were both even. Whey!

Reply 3

Olie

20

Wasn't expecting it to be too easy after Jan 09, which judging by the grade boundaries was probably the easiest C1 paper ever but I think today's was alright tbh, bit unsure about a few questions that I hadn't come across before but overally I think I've done enough to get what I need.

And btw, what did people get for the point of contact on the last question, I think I got it right after a few minutes of thinking but not entirely sure.

Reply 4

Mr Nonsense

13

chemcat

I thought it was ok. But lots found it hard. I missed the bit about stating the y-intercept when it was translated by 3 across. Just didn't see it. Did the rest of that part but missed that totally.

The only "hard" question was the n^3-n one where you had to prove it was even for any integer. I just subbed in 2k to show it was even for even numbers and 2k+1 to show for odds. They both were divisible by 2, so were both even. Whey!

for that one i factorised, then did an "if n is even.." and "if n is odd..." argument. Not as good probably but hey, should still get me the marks hopefully.

What other answers did you get?

Last question, tangent to circle bit at (1,4)?

Area of triangle = 9

umm.. can't remember the questions.

There was nothing on the back page was there?

Reply 5

Mr Nonsense

13

Olie

Wasn't expecting it to be too easy after Jan 09, which judging by the grade boundaries was probably the easiest C1 paper ever but I think today's was alright tbh, bit unsure about a few questions that I hadn't come across before but overally I think I've done enough to get what I need.

And btw, what did people get for the point of contact on the last question, I think I got it right after a few minutes of thinking but not entirely sure.

(1,4) i think

Reply 6

Mr Nonsense

13

1032669654

think i had (1,4) for the point of contact.

-

for the proof question i factorised n^3 - n to n(n^2 -1)

Then showed if n is even, n^2 -1 is odd, so odd x even = even

And when n is odd, n^2 -1 is odd, so again odd x even = even

Dyou think this is also a suitable method?

that is exactly what i did- so i hope so

Reply 7

chemcat

1032669654

-

for the proof question i factorised n^3 - n to n(n^2 -1)

Then showed if n is even, n^2 -1 is odd, so odd x even = even

And when n is odd, n^2 -1 is odd, so again odd x even = even

Dyou think this is also a suitable method?

Yeah that's probably fine, imagine it's pretty much the same as mine but i subbed then factorised...

Reply 8

Mr Nonsense

13

1032669654

think i had (1,4) for the point of contact.

-

for the proof question i factorised n^3 - n to n(n^2 -1)

Then showed if n is even, n^2 -1 is odd, so odd x even = even

And when n is odd, n^2 -1 is odd, so again odd x even = even

Dyou think this is also a suitable method?

there was a similar question in the Jan 08 paper - "Prove that 12 is a factor of 3n^2 + 6n for all even positive integers n."

And the markscheme says as an alternative method - "or M1 for 3n^2 + 6n = 3n (n + 2) = 3 × even × even and M1 for explaining that 4 is a factor of even × even or M1 for 12 is a factor of 6n when n is even and M1 for 4 is a factor of n^2 so 12 is a factor of 3n^2"

Reply 9

T=RC

solid, grade boundaries better be low!

Reply 10

LearningMath

14

I thought it was an ok paper, not sure for the proof question though. I said if n=even integer than even*even=even etc etc and same for odd.

Btw i have a copy of the paper here, i am happy to post the paper if anyone wants to look through it, but i best check with mods first...

Reply 11

BiGBaDBoO

OP

I found question 11 incredibly hard, although in hindsight you can still get an A even if you drop like 14 marks and i doubt i dropped that many. I also got (1,4) as the contact. But didnt really know how to prove it as a tangent, although surely just getting one point of contact would do that to a certain degree?

Reply 12

kennykwan

Can be proven by the gradients and the distance from the tangent to the centre being the same length as the radius?

Reply 13

LearningMath

14

BiGBaDBoO

I found question 11 incredibly hard, although in hindsight you can still get an A even if you drop like 14 marks and i doubt i dropped that many. I also got (1,4) as the contact. But didnt really know how to prove it as a tangent, although surely just getting one point of contact would do that to a certain degree?

To prove tangent you had to factorise and actually write 'repeated root implies tangent' or anything to that effect. You probably factorised if you got 1,4. But you needed to actually say why it was a tangent as well :smile:

Reply 14

Mr Nonsense

13

LearningMath

I thought it was an ok paper, not sure for the proof question though. I said if n=even integer than even*even=even etc etc and same for odd.

Btw i have a copy of the paper here, i am happy to post the paper if anyone wants to look through it, but i best check with mods first...

yes please do post it!! makes it easy to check through

It is only edexcel where it matters, so should be fine

Reply 15

Mr Nonsense

13

BiGBaDBoO

I found question 11 incredibly hard, although in hindsight you can still get an A even if you drop like 14 marks and i doubt i dropped that many. I also got (1,4) as the contact. But didnt really know how to prove it as a tangent, although surely just getting one point of contact would do that to a certain degree?

which was question 11? The line AB one with find the area of the triangle and stuff?

I showed it was a tangent as it had a repeated root and so two identical intersections --> it osculates with the circle

Reply 16

Toneh

8

i thought it was easy
until i completely skrewd up the question with x^4 + 5x^2 - 36 and lost 5 marks or whatever it was out of :frown:

Reply 17

Mr Nonsense

13

LearningMath

To prove tangent you had to factorise and actually write 'repeated root implies tangent' or anything to that effect. You probably factorised if you got 1,4. But you needed to actually say why it was a tangent as well :smile:

i said that the equation had two repeated roots and so the line 'intersects' twice at the same place and so it is must just be 'kissing' the circle and so tangent

do you think that would be ok?