Current Year 12 Thread Mark I (2012-2013)

Only thing I don't understand now is how 3x-2nx=-11x why is it -11 I thought -6 would be a part of it.

No, -6 is where you got the 2 and -3 and the end of both factors.

See:

$(x-2)(2x^2 + nx + 3)$

$= x(2x^2 + nx + 3)-2(2x^2 + nx + 3)$

$= 2x^3 + nx^2 + 3x - 4x^2 - 2nx -6$

$= 2x^3 + nx^2 - 4x^2 + 3x - 2nx -6$

$= 2x^3 + (n - 4)x^2 + (3 - 2n)x -6$

Referring to your original equation:

$2x^3+3x^2-11x-6 \equiv 2x^3 + (n - 4)x^2 + (3 - 2n)x -6$

So you could either use n-4=3 or 3-2n=-11

Oh so I can choose them in the equation say for this equation x^3-3x^2+3x-1 for my nx factor I can choose 3x= x-nx is that true for most questions in c2?

Yes, that'll work for factorising any cubic equation.

Getting extremely frustrated with this equation $x^3-x^2-3x+3=0$ so far I found out that the coefficients add up to make 0 so $(x-1)$ is a factor then I have$(x-1)(x^2+nx-3)$ the problem is my equation

Divide both sides by x

-3-1n=-3

Alternatively, you could just cancel out the -3x on both sides of the equation, and divide the x from -1nx into the zero on the RHS.

Solved it on another forum ages ago, I got to that stage and realized it is just 0 thanks anyway

No problem, and sorry for the late reply

yeah short sentences

lol i swear u used to have it, like rock and rose. something

Did my first chemistry past paper tonight and got 74% - not too bad to say we haven't finished learning everything yet. :')

a B. Not too shabby on your first attempt. Congrats, I think I'll do that next week for every subject let's hope I'm revising efficiently

My first ever A-level past paper.
How are you revising for each subject? :')

Psychology, I'm just going over notes, going over textbook, proper understanding everything before I move on, ask people to ask me questions.

The rest I've started typing up notes so I can read it, as it'll be way more neat. Also hope to include photos and images

I'm doing something similar for biology and chemistry. I'm writing up all my notes in different words and going through the specification. But I'm handwriting everything and my French teacher keeps giving me loads of work so it's going to take ages. I can't believe it's already time to start revising.

Hey everyone, this is a question for everyone who does AQA Physics A.

What textbook do you use, and what is the best textbook to use in your opinion? Of course the CGP book is only a revision guide, but the examples in it are too simple (the mechanics questions aren't exam standard). The AQA endorsed book by Nelson Thornes covers everything but a few things have really annoyed me and kept me behind so far until I got learned it in M1 maths. The mechanics section is written stupidly, putting a prerequisite in learning their page on Trig. at the back of the book. Then the "worked example" is done fully algebraically and they don't actually answer any question in the "example".

Well then I have now understood the topics and can do the summary questions. But there are no answers for the exam style questions! If I use all of the online papers from the internet to weed out relevant questions now I'll have nothing to test myself with come exam time.
I'm not complaining just wondering if anyone does know of a better textbook. I wouldn't mind carrying on this way, but just in case there was a reasonably better resource I'd rather find out now than later.

Hi! I also do AQA Physics A, and while I can't help you by offering another textbook (I personally haven't found any problems with it, but we've barely covered half the unit ) I do have the answers to the Exam-style questions, if you'd like them? I'm not entirely sure how to get them to you though