Edexcel A2 C3 Mathematics 12th June 2015

How do people go about range and domain question, I always think I understand them but then I always get it wrong :| I draw out the diagram but still seem to get it wrong. How would you do this ? (Its the c3 practise paper 2)

Reply 603

Mr T Pities You

3

Original post by humayra.ac

How do people go about range and domain question, I always think I understand them but then I always get it wrong :| I draw out the diagram but still seem to get it wrong. How would you do this ? (Its the c3 practise paper 2)

I guess you're talking about part b for the range?
Think of the graph for this. Use the domain (x>1). Can the fn ever be negative? What happens when x is really close to 1? What happens as x tends to infinity?
Using these few prompts can help you.

Reply 604

humayra.ac

yes part b, hmm ok thanks. Would you apply this thought process for all questions

Original post by Mr T Pities You

I guess you're talking about part b for the range?
Think of the graph for this. Use the domain (x>1). Can the fn ever be negative? What happens when x is really close to 1? What happens as x tends to infinity?
Using these few prompts can help you.

Reply 605

Mr T Pities You

3

Original post by humayra.ac

yes part b, hmm ok thanks. Would you apply this thought process for all questions

Something similar, yes, but particularly when there are fractions. If the fraction is 'top heavy' then divide it first, as it really helps! Always use the domain of the function if it's not just all the reals.
If the question involves anything about an inverse function, then know that you'll have to use the relationship between range and domain of functions and their inverse.
Cheeky, but keep an eye on the number of marks. A one marker indicates that no calculation is necessary so the chances are that the answer is in the question.

Reply 606

Shamla

http://www.physicsandmathstutor.com/maths-revision/a-level-core-3/

This website has everything you'll need :smile:

check out the cheat sheet as it helps you realise the common mistakes per chapter and also check out the practice papers! Hope it helps :smile:

Original post by Kill3er

Since our school has just finished teaching all the content for the Core 3 Edexcel exam, i think it would be a good time to get a thread going.

How's revision going? How are people doing with past papers? Which topics are you finding most difficult? Feel free to post any questions, and hopefully someone will be able to help.

Edexcel C3 - Friday 12^th June 2015

Hopefully this thread will motivate us all, and help us to achieve the grades we deserve.

Useful Links
Specification - http://www.edexcel.com/migrationdocuments/GCE%20New%20GCE/UA035243_GCE_Lin_Maths_Issue_3.pdf
Forumlae Booklet - http://www.edexcel.com/migrationdocuments/GCE%20Curriculum%202000/[ARCHIVED]%20N38210A-GCE-Mathematical-Formulae-Statistical-Tables.pdf
Offical Past Papers - http://www.mathspapers.co.uk/edexcel.html

Examsolutions - www.examsolutions.net
Maths247 - www.m4ths.com
Question Booklets/Past Papers - http://www.madasmaths.com
C3 Solomon Papers - http://www.physicsandmathstutor.com/a-level-maths-papers/c3-solomon/
Gold/Silver/Bronze Papers - http://mathstallis.weebly.com/past-papers.html

If you have any other websites you'd like to add, post them below and i'll edit this post.

Edexcel C4 June 2015 - Official Thread

Reply 607

humayra.ac

ok thanks

Original post by Mr T Pities You

Something similar, yes, but particularly when there are fractions. If the fraction is 'top heavy' then divide it first, as it really helps! Always use the domain of the function if it's not just all the reals.
If the question involves anything about an inverse function, then know that you'll have to use the relationship between range and domain of functions and their inverse.
Cheeky, but keep an eye on the number of marks. A one marker indicates that no calculation is necessary so the chances are that the answer is in the question.

Reply 608

jadys10

Original post by edothero

Think about the main equation.

T = 400e^{-0.05t}+25

where temperature

= T^{\circ}

Spoiler

I still don't fully understand this. It saids can't fall below 20 degrees, but the formula gives +25

Reply 609

zed963

16

Original post by jadys10

Can anyone explain question 4d to me on this paper:
http://eiewebvip.edexcel.org.uk/Reports/Confidential%20Documents/0606/6665_01_que_20060612.pdf

When t tends to infinity, the 400e^t becomes very small approaching 0 . Since the constant is 25, the temperature can never fall below 20.

Reply 610

MasonPye

Are we meant to revise proof by contradiction and counter-example?

Reply 611

MasonPye

And could someone tell me what's going on with Q6b, is that integration in a C3 paper? If someone could help me out that would be great. Here's the link: https://aeb44e76c1fb598b02a447aec2866c6b846371c4.googledrive.com/host/0B1ZiqBksUHNYXzgxRS15M3dxU28/Practice%20Paper%20A1%20QP%20-%20C3%20Edexcel.pdf

Reply 612

jadys10

Original post by zed963

When t tends to infinity, the 400e^t becomes very small approaching 0 . Since the constant is 25, the temperature can never fall below 20.

Ok thanks

Reply 613

aersh8

Original post by MasonPye

Are we meant to revise proof by contradiction and counter-example?

They aren't on the syllabus so no.

Reply 614

games211

16

Original post by MasonPye

And could someone tell me what's going on with Q6b, is that integration in a C3 paper? If someone could help me out that would be great. Here's the link: https://aeb44e76c1fb598b02a447aec2866c6b846371c4.googledrive.com/host/0B1ZiqBksUHNYXzgxRS15M3dxU28/Practice%20Paper%20A1%20QP%20-%20C3%20Edexcel.pdf

integrate it first then sub all x values with 3

Reply 615

grn

Original post by MasonPye

And could someone tell me what's going on with Q6b, is that integration in a C3 paper? If someone could help me out that would be great. Here's the link: https://aeb44e76c1fb598b02a447aec2866c6b846371c4.googledrive.com/host/0B1ZiqBksUHNYXzgxRS15M3dxU28/Practice%20Paper%20A1%20QP%20-%20C3%20Edexcel.pdf

Looks like it! It is pretty basic C1 integration so technically they are allowed to include it, I doubt they would in an actual C3 exam though.

Reply 616

luckystar1900

Original post by MasonPye

Are we meant to revise proof by contradiction and counter-example?

Haha, do you ask this because of that solomon paper? I had no idea how to do that question!! Although not specifically on the syllabus maybe they could ask it as it is briefly mentioned at GCSE, albeit much simplified?? I don't think we need to worry about it though :smile:

Reply 617

aersh8

Original post by luckystar1900

Haha, do you ask this because of that solomon paper? I had no idea how to do that question!! Although not specifically on the syllabus maybe they could ask it as it is briefly mentioned at GCSE, albeit much simplified?? I don't think we need to worry about it though :smile:

Hope they don't - we didn't even hint at that in CIE IGCSE, but counter example sounds intuitive enough (just find a value for which the statement isn't true), whilst contradiction may (or may not) be a case of algebraic fiddling until RHS isn't equal to LHS so maybe if they do decide to give it to us we can figure it out on the spot without previous experience. At least that's the impression I got from the questions in Solomon.

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Reply 618

samb1234

13

Original post by luckystar1900

Haha, do you ask this because of that solomon paper? I had no idea how to do that question!! Although not specifically on the syllabus maybe they could ask it as it is briefly mentioned at GCSE, albeit much simplified?? I don't think we need to worry about it though :smile:

Someone else posted before that their teacher had emailed edexcel about counter example contradiction etc as they aren't in the textbook and they were told that they are no longer part of our specification

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Reply 619

luckystar1900