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C2 June 2011 Edexcel - Paper and Solutions in the FIRST post.

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[QUOTE="Pi!;31694321"]How do you solve this simultaneous equation?

log(2)x + log(8)y= -1
log(4)/SIZE]x + log(2)y= 2

Change all the log bases to 2.
so that would make the first log function equation
log(2)x + 1/3 log(2)y= -1
And the second one would be
1/2 log(2)x + log(2)y= 2

You can then solve it like a regular simultaneous equation.

Reply 381

godknows

Original post by snow leopard

C2 Chapter 9. Someone please explain the whole 'range of values' business in section 9.2; if you haven't got the book take a look at the following example I've written up.

----------------------

Find the greatest value of 6x-x^2,

Let y=6x-x^2,
dy/dx=6-2x
dy/dx=0, 6-2x=0, x=3,
therefore y=9

Greatest value of this quadratic function is 9, range given by f(x)=<9

What does it mean about 'range given by', why is there a range at all, what in the where in the why :s-smilie:

by the range given by f (x) = <9 they mean tht any value of x bigger then 9 would not work in the formula y = 6x - x^2

Reply 382

neemee

For binomial expansion can we use the nCr button on our calculator or do we have to write out the factorials?

Reply 383

mintmocha

Original post by neemee

For binomial expansion can we use the nCr button on our calculator or do we have to write out the factorials?

You can use the nCr button but make sure you write it down in your paper. For instance; 1^5 + 5C1 (1)^4 (x) + 5C2...etc.

Reply 384

snow leopard

Original post by godknowsprerna

by the range given by f (x) = <9 they mean tht any value of x bigger then 9 would not work in the formula y = 6x - x^2

Right. And in a question how do you know whether to use >= or =<? Does =< correspond to 'greatest' and >= to 'smallest', is that how it works?

Reply 385

godknows

Original post by snow leopard

Right. And in a question how do you know whether to use >= or =<? Does =< correspond to 'greatest' and >= to 'smallest', is that how it works?

yhh so < means the greatest value of x which will work in the formula and > means the smallest value of x which will work :smile:

Reply 386

snow leopard

Original post by godknowsprerna

yhh so < means the greatest value of x which will work in the formula and > means the smallest value of x which will work :smile:

Life saver.

Reply 387

neemee

Original post by mintmocha

You can use the nCr button but make sure you write it down in your paper. For instance; 1^5 + 5C1 (1)^4 (x) + 5C2...etc.

Thank you

Reply 388

F1's Finest

all i need is a D in this paper ( providing that my s1 paper is a low A ), then i get my A overall, how cool !!!

but we need as many marks as possible to carry forward into A2, coz most students dont do well on c3 and c4 according to my maths teacher.

Reply 389

zumgluck

Does anyone know how to answer this question:
[URL="

Reply 390

5araol

Original post by zumgluck

Does anyone know how to answer this question:
[URL="

Please dont tell me that this is a past paper question/something which we should know ?

Its very hard :frown:

Reply 391

KKKKatie

Original post by Arsey

yes but shop around, you will prob find it a bit cheaper.

The 991es is an awesome calc, I would recommend every A2 student having one.

I'm in love with my 991esPLUS my most prized possession (almost)

Reply 392

Insanity514

Do we need to know about changing log bases? We haven't been taught it

Reply 393

Insanity514

Original post by zumgluck

Does anyone know how to answer this question:
[URL="

http://www.srepapmaxeeeerf.org/A%20Level/Maths/Edexcel/C2/C2%20Mock%20paper%20MS.pdf

Mark scheme.

Reply 394

gdunne42

Original post by zumgluck

Does anyone know how to answer this question:
[URL="

This is just a slightly different way of saying the coefficient of the x^2 and x^3 terms are equal.

Expand as normal using the second form of the expansion in the formula page - not forgetting the k
Equate the coefficients and simplify to the required solution

Reply 395

gdunne42

Original post by Insanity514

Do we need to know about changing log bases? We haven't been taught it

Yes
Though I don't recall there ever being a question on a real C2 paper
The method is on the formula page if you need it

Reply 396

zumgluck

Original post by 5araol

Please dont tell me that this is a past paper question/something which we should know ?

Its very hard :frown:

It's on a mock paper from that website Arsey gave.

Reply 397

KKKKatie

for binomial expansion, i've only ever used the 1 + nx+ n(n-1)/2! x^2 etcc method, will this work with all questions or do i need to learn the nCr one as well? also when its something like (6+x)^5 what do i do with the 6, because it always comes out wrong for me, help would be greatly appreciated!

Reply 398

Eat.Sleep.Row.Repeat.

I've never been taught how to use factorial with binomial expansion...I always use nCr?

When are you supposed to use factorial? Because if a paper comes up like Jan 11 q5 I'd have no idea what to do...

Reply 399

KKKKatie

I've just always used it, it seems a lot simpler eg (1+x)^5 would just be (first three terms):

1+5x+5(5-1)/2! x^2

= 1 + 5x + 10x^2

i hope i havent been doing it wrong all this time haha