OCR C2 Exam May 18th 2012

can anyone help meeee?? please?
sin2x = -cos2x
how do i solve this? its so simple but i cant figure out how to do it
Thankyou x

what is angle BC? :s

can anyone help meeee?? please?
sin2x = -cos2x
how do i solve this? its so simple but i cant figure out how to do it
Thankyou x

Also... Another minor question but, when do you know when to leave a fraction as top heavy or mixed? Sometimes in the mark scheme it's mixed and sometimes not. Would I still get a mark if I left it in a different form?

It doesn't matter, the mark scheme always says e.g. 5 1/3 and in the comment column "or any identical answer". So it does not matter

Im going to use A for arithmetic and G for geometric

A1=G1 therefore a = a
A2=G2 therefore a+d = ar
A3=G4 therefore a+2d = ar^3

A1 + A3 = 2A2 therefore G1 + G4 = G2, therfore a + ar^3 = 2(ar)

See where it is going?

And yeah I meant for that, I dont know how to solve a cubic in this case without factor theorum, but it just didnt feel very mathematical taking a factor out that way without being told to like normal.

EDIT: Yes the log thing was a deduction, but I am not very intelligent so yeah I do not notice these things

I've come across a question on Jan 11 ocr c2, that says find the sum of 200 where n = 101. it's one of those sequence symbols.. what does this mean?!

i dont understand the n = 101 part.

Why do you need BC for part ii)? (if you dont mean BAC) and anyway with the angle BAC you know from part i) you should be able to find the other angles with the sine rule, but I cant see why you need it.

i did that now, but the mark scheme for part 3 confuses me, ive found angle C but the mark scheme says to do 290 - angle C

or 210 + angle A

but i dont get why

can anyone kindly help me with a question...
its 9ii) i dont understand the question and which values of x to use...
Thank you..!

Is it just from 0-2? so 0, 0.5, 1, 1.5, 2?

Yea I see. Thanks for this btw and then what would you have done?

And oh, I don't mean a deduction from my part ha, its just in my book it doesn't really state it as a rule, it just says that this implies this and so use it to effect - tbh I think it is basically a rule, as its the whole point of logs, right?

Because you are looking for the angle that goes from the north of C to the parth CA CLOCKWISE. You know the the angles from the left of north C to BC is 70, (as the angle above it at B is 110, like in part i), then you are left with angle BCA, which you find, then do 360 - BCA - 70 = answer, so 290 - BCA.



Yes it is, the curve you are after has an asymptote with the x-axis, i.e. it never touches it, meaning subbing y=0 into it wont find any x-intercept, you were meant to take the hint that the upper limit was 2, and there were 4 strips of 0.5 and work backwards to 0 (it also says area bound by the axis).



Well, what I did then was rearrange and take the common factor of a out, which leaves you witht he equation they asked for.

Yeah lets call it s log rule, saves the arguments

Oh okay... i didnt quite understand their wording but after your explanation i get it now Thank you very much..! im sure you'll ace it tmr

I'm aiming for 90+ getting 89 was annoying in C1 as I am aiming for A* in Maths and Further maths, and it would have knocked my confidence if it wasnt for my FP1 score, I learned my lesson not to neglect these early Core units even though they are viewed as easier by many people, because towards your AS and A2 they are worth the same amount of UMS.

I hope I will do well, I seem to be helping out a lot so I cant be that bad :P

I did the May 2011 paper just before and got 72/72 so Im feeling good, I almost slipped up at the end, with a 2x graph I nearly took an x value and halved it again, but I realised while checking though the question

Well, what I did then was rearrange and take the common factor of a out, which leaves you witht he equation they asked for.

Yeah lets call it s log rule, saves the arguments