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Edexcel C3,C4 June 2013 Thread

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Reply 2500

Revisionbug

Anyone up for some friendly competition to get full ums in both c3 and c4 :colone:

Reply 2501

MathsNerd1

Original post by Revisionbug

Anyone up for some friendly competition to get full ums in both c3 and c4 :colone:

Bring it on!! :colone:

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Reply 2502

nukethemaly

Original post by Lamalam

Is c3 solomon paper worth doing? Coz i am afraid i dont have much time to finish them all @@

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Do like a few of them

Reply 2503

JenniS

now M2 and M3 are over, solid C3 til thursday

Reply 2504

BobLoblawLawBlog

Could someone help me with 7(b) on Solomon paper K.

Spoiler

I was just wondering whether these two answers are equivalent, and if not, then where have I gone wrong. Thanks.

Reply 2505

justinawe

Original post by brittanna

Could someone help me with 7(b) on Solomon paper K.

Spoiler

I was just wondering whether these two answers are equivalent, and if not, then where have I gone wrong. Thanks.

I'm pretty sure they're not equivalent.

How did you get [latex\]\tan^2 \theta=\frac{1}{4}(x-\frac{1}{x})^2 and

4\cot^2 \theta=(y-\frac{1}{y})^2

Reply 2506

Anjna

is the c3 and c4 exam in the morning or afternoon?

Reply 2507

MathsNerd1

Original post by Anjna

is the c3 and c4 exam in the morning or afternoon?

Morning I believe. :smile:

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Reply 2508

Story

Hey guys wondering if anyone could help me.

For the C3 Jan 08 paper Q)1) I used the method of equating coefficients instead of long division, and I got the first part right which is (2x^2-1).

My questions is how do you get the second part the (dx+e) bit.

Do I do (2x^2-1)(dx+e)=2x^4-3x^2+x+1. Then equate coefficients?

Any guidance, tips or help is appreciated!

Wait...I think I get it, do you do (dx+e)(1)=2x^4-3x^2+x+1.
Thus d =1.
But how is e=0... I though you would have done e=1?

(edited 10 years ago)

Reply 2509

Delusional09

Original post by Anjna

is the c3 and c4 exam in the morning or afternoon?

Both Exams are in the morning. :smile:

Reply 2510

Delusional09

I really don't understand what you mean by equating the coefficients, but I always do long division. Once you've done the long division your remainder should be x . Because your remainder is x, you write it on top as (dx+e) So your d=1 and e=0 as there is no e. So your overall equation would be (2x^2 - 1) + x all over (x^2 - 1). Where a=2 b=0 c=-1 d=1 and e=0. Hope this helps. :smile:

Reply 2511

BobLoblawLawBlog

Original post by justinawe

I'm pretty sure they're not equivalent.

How did you get [latex\]\tan^2 \theta=\frac{1}{4}(x-\frac{1}{x})^2

and

4\cot^2 \theta=(y-\frac{1}{y})^2

4+4tan^2\theta=x^2+2+\frac{1}{x^2}

4tan^2\theta=x^2-2+\frac{1}{x^2}=(x-\frac{1}{x})^2

\Rightarrow tan^2\theta=\frac{1}{4}(x-\frac{1}{x})^2

I got

4cot^2\theta=(y-\frac{1}{y})^2

in the same way, but using the equation with y instead of x. It doesn't look like the two answer are equivalent, so I just want to know where I went wrong.

(edited 10 years ago)

Reply 2512

Better

Original post by brittanna

4+4tan^2\theta=x^2+2+\frac{1}{x^2}

4tan^2\theta=x^2-2+\frac{1}{x^2}=(x-\frac{1}{x})^2

\Rightarrow tan^2\theta=\frac{1}{4}(x-\frac{1}{x})^2

I got

4cot^2\theta=(y-\frac{1}{y})^2

in the same way, but using the equation with y instead of x. It doesn't look like the two answer are equivalent, so I just want to know where I went wrong.

Brittanna thanks so much for the Tips on how to use your the Calculator to check back my answer. Surprsingly it's not even about the Calculator but how you think about Maths - verifying whether your logic is rigorous enough.

Just did C3 Jan 2013, surprisingly the Calculator stopped me from making horrendously horrible errors. I think I was a bit had a bit of Anxiety whilst I was doing it; but definitely great I did it today: Felt like an exam.

If anyone sees a question they don't get 100% remember to just Keep on Going.

It sounds silly but what I do for Chemistry and Physics, is when I'm stuck I flip to an Easy Question which is worth like 10 Marks and do that in 3-5 minutes and then go back again. It's what I just did on C3, and it definitely worked.

From doing this it is very easy to maintain momentum.

How to Solve it: A New Aspect of Mathematical Method - George Polya
http://www.math.utah.edu/~pa/math/polya.html

(edited 10 years ago)

Reply 2513

BobLoblawLawBlog

Original post by Better

That's kind of what I do in physics. Although for me it's more when my hand starts aching, i'll go and do some of the calculations (which are also usually easier) :tongue:

.

But yeah, although it isn't good to become too dependant on calculators, they can be a really big help as well.

Reply 2514

Better

Original post by brittanna

That's kind of what I do in physics. Although for me it's more when my hand starts aching, i'll go and do some of the calculations (which are also usually easier) :tongue:

.

But yeah, although it isn't good to become too dependant on calculators, they can be a really big help as well.

I'm glad I'm not the only one then.

I may just start off with the Essay Style Questions on Wednesday, before I do anything else!

But back to work, thanks again - time for me to do Chem 5 Jan 13, then Phys 5 Jan 13.....then argh chem 4 work after that al night...

Reply 2515

JenniS

Has anyone got that black thick A2 core for edexcel textbook, if so question 5a on the sample exam paper I'm stuck (C3)

Reply 2516

justinawe

Original post by brittanna

4+4tan^2\theta=x^2+2+\frac{1}{x^2}

4tan^2\theta=x^2-2+\frac{1}{x^2}=(x-\frac{1}{x})^2

\Rightarrow tan^2\theta=\frac{1}{4}(x-\frac{1}{x})^2

I got

4cot^2\theta=(y-\frac{1}{y})^2

in the same way, but using the equation with y instead of x. It doesn't look like the two answer are equivalent, so I just want to know where I went wrong.

Actually, after subbing in values, I think they may actually be equivalent. But I'm not sure how to justify it.

I'm not sure if you can just square root both sides like you did though, you need to account for negative roots as well.

Reply 2517

Lamalam

hey guys, I am quite confused about the edexcel c3 june 2006 q5a,

and here is how I worl the question

, am I correct?

i am confused about the cancelling of cos^2 (2K), why can it be eliminated?
my teacher told me that
if x^2 = 2x , I cannot cross out anything but putting the 2x on the same side as x^2 and carry on working.
why in the q5, the cos^2 (2k) can be eliminated? will this cause a loss of answer?
in what situation can a quantity be eliminated?

thank you soooo much!! please help!