Monday 14 Jan 2013 - CORE MATHEMATICS ( Edexcel) OFFICIAL THREAD FOR DISCUSSIONS

Thanks

R u doing edexcel S1, if u are and your finding probability easy, can u give me some advice?

I have posted these in the A Level thread but they may help:

Solomon A
http://www.youtube.com/playlist?list=PLS8c-8fhVcdHmyuKi1OECKyuH6CuScu-n

Solomon B
http://www.youtube.com/playlist?list=PLS8c-8fhVcdEr4lkPwX9OWrxnrJ2IGiWN

Full C1 revision playlist (with some long old videos!!)
http://www.youtube.com/playlist?list=PLS8c-8fhVcdESuHXQS1c0hYkja9yzrJoT&feature=view_all

May help some of you.
All the best with your exams

More great resources for me to use! God bless you, thank you very much!


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yes im doing C1,C2 and S1 in january how did you guess that XD.
i used to find s1 really hardd and confusing but im getting the hang of it now.
with probablity try to have an open mind and ensure you read the question very careful to know what statistic they are looking for and how to get it.
and remember the independent rule since thats likely to come up and its easy marks. the part i see people getting confused on is "find A given B", practise using the formula for it (its on the s1 formula sheet btw! )

http://www.examsolutions.net/maths-revision/syllabuses/Edexcel/period-1/S1/module.php
this website explains probablity quite well so check it if you havent already.

Do u think if u can remember the formulas for independence and A given B and the others u should be able to do every question?

Im doing the C1 exam week after next and I have been doing lots of past papers, but I cant do some of the questions or I get stuck and Im really worried! I also make a lot of silly mistakes! Any advice or revision tips?

Can someone please help me with this question?
Factorise 4x-3x^2-x^3
The answer is x(1-x)(4+x)
I don't understand how they came to this answer
Thanks

$-x^3-3x^2+4x$ take out a common factor of x so
$x(-x^2-3x+4)$ factorise the bracket inside to get
$x(1-x)(4+x)$

But how did you get the last bit? I understand the first 2 steps but i don't understand the last bit. Can you explain that in a little more detail please? Thanks

Sorry for being away I had a shower! anyway so we have x(-x^2-3x+4) we need to factor this so start of with $(-x )(x )$ we know from this that $-x$ multipled by $x$ gives us $-x^2$ further more we know that we need two numbers that multiply to give $4$ If we look clearly at the numbers $-x$ multiplied by $4$ gives us $-4x$ and $x$ multiplied by one gives us
$1x$ then $-4x +1x = -3x$ which is part of the equation and 1x4=4 so factorised x remains on the outside for the cubic this means $x=0$ if you were asked to solve and then graph it. can you see now how
$x(-x^2-3x+4)$ goes to $x(1-x)(4+x)$ ? if you actually expand the brackets inside you are given $-x^2-3x+4$ sorry if it's not very clear negative quadratics require just a bit of experimenting, but they usually are the same two numbers that multiply to give $4$ and then two numbers than multiplied then added together to give $-3x.$

It's alright. So we just have to experiment with which numbers fit? This is how we get them to remain in the same order right? Thank you for the help...i think i get the gist of it now

Well not exactly experiment but try combinations that multiply to give 4 and then go from there, obviously there's a limited amount of whole numbers. But if you pretend and visualise you've written it down cross multiply across the brackets then you'll see whether it gives you -3x or not! No problem, I'm doing well at solomon papers so literally any question your stuck on I can help with !

Aw thank you i shall definitely ask u if i'm stuck! i just started solomon papers today...a bit harder than edexcel papers but i'm coping. So are you ready for C1? what else are you doing in terms of revision btw? all i'm doing are the solomon papers, the edexcel papers and questions from the text book but i feel like i need to do more :/ you see i'm never confident in maths no matter how much revision i do

Aw thank you i shall definitely ask u if i'm stuck! i just started solomon papers today...a bit harder than edexcel papers but i'm coping. So are you ready for C1? what else are you doing in terms of revision btw? all i'm doing are the solomon papers, the edexcel papers and questions from the text book but i feel like i need to do more :/ you see i'm never confident in maths no matter how much revision i do

dont worryyy, thats more than enough to prepare you for the exam!
do the papers and go over the topics you are weakest at and you should be finee.

I literally did so much revision at the start that put me ahead of everyone who did on and off revision, so now I'm doing 1 solomon paper a day leading up to the exam up to solomon paper I, being getting 60-75 but more close to 70-75 recently. Other revision is honestly non existent, I've exhausted x2 textbook load of questions.

I'm really ready for c1, aiming for 100 ums (and want to do maths at university)
if your losing marks on areas I'd definitely go to examsolutions, or just practice questions purely on that chapter past papers are always good, half the questions in the textbook help the understanding, with the exam it's application that's essential and understanding.. Only once in the holidays though did I need to practice on my asymptote skills other then that I've become very acquainted with c1, history unit 1 and economics unit 1, hoping to score 90%+ in all of them, what exams have you got and how are you feeling about them?

Well done you for thinking ahead and starting preparation early! That's really good marks you're getting with the solomon papers. Well seeing that you're trying extremely hard i'm sure it's possible for you to get 100 UMS Maths at uni? woah do you like maths that much? i've got just one other exam- chem unit 1. Prepared better for that than maths...that's why i'm really working my ass off for maths now. I did do more revision for maths than chem i guess from like the beginning of when school started that's why i concentrated more on chem during the holidays. Good luck with your exams then (: