Year 13 Maths Help Thread

Announcements Posted on
How helpful is our apprenticeship zone? Have your say with our short survey 02-12-2016
    Offline

    3
    ReputationRep:
    Thanks again.
    Offline

    3
    ReputationRep:
    (Original post by Palette)
    (special mention to Zacken for putting up with my silly C3/C4 inquiries!).
    (Original post by Palette)
    with credit due to the helpers (especially Zacken) for making this project work!
    Woot! Thanks for the special mention! Great thread, props to you. I'd like to have a special shout out to SeanFM for his invaluable help here and elsewhere.
    Offline

    2
    ReputationRep:
    To those going on to A2 maths... please, please don't ever underestimate the subject! It doesn't matter if you're breezing through gold papers, maths is completely unpredictable. At the same time, don't give up if you find you're just spinning your wheels. Your maths skill over the next year will be like an exponential curve; you'll surely get the hang of it around February-April

    Maths alone needs to be the majority of your revision. There's hardly any memory involved in maths aside from remembering previous past paper questions. It's all practice. There's a saying; the more I prepare, the luckier I get. During study leave, your revision has to increase in intensity right up to the exam day, and you cannot afford to leave gaps in the year where you haven't practiced maths papers. Your ability will falter.

    I am by no means a good mathematician. This is just advice from a wounded survivor. Good luck, and appreciate the unique challenge the subject gives you. I'll always be envious of those gifted in mathematics.
    Offline

    2
    ReputationRep:
    (Original post by hopefuldentist10)
    To those going on to A2 maths... please, please don't ever underestimate the subject! It doesn't matter if you're breezing through gold papers, maths is completely unpredictable. At the same time, don't give up if you find you're just spinning your wheels. Your maths skill over the next year will be like an exponential curve; you'll surely get the hang of it around February-April

    Maths alone needs to be the majority of your revision. There's hardly any memory involved in maths aside from remembering previous past paper questions. It's all practice. There's a saying; the more I prepare, the luckier I get. During study leave, your revision has to increase in intensity right up to the exam day, and you cannot afford to leave gaps in the year where you haven't practiced maths papers. Your ability will falter.

    I am by no means a good mathematician. This is just advice from a wounded survivor. Good luck, and appreciate the unique challenge the subject gives you. I'll always be envious of those gifted in mathematics.
    Thanks for your advice, I appreciate it. Unlike last year, this time i will listen to older students and start revising early!!
    Offline

    2
    ReputationRep:
    (Original post by RDKGames)
    Congratulations! Don't worry, A2's will be a breeze if you keep it up. :congrats:
    Thank you!! Haha hopefully
    Online

    3
    ReputationRep:
    (Original post by Zacken)
    Woot! Thanks for the special mention! Great thread, props to you. I'd like to have a special shout out to SeanFM for his invaluable help here and elsewhere.
    A moment of silence for some disappointed Warwick Admissions Tutors. And a well done.
    Offline

    3
    ReputationRep:
    (Original post by SeanFM)
    A moment of silence for some disappointed Warwick Admissions Tutors. And a well done.
    Thank you very much!
    • Thread Starter
    Offline

    2
    ReputationRep:
    I spent age doing a relatively simple trigonometry question as I mislabelled 6\cos \theta and 6\sin \theta because I drew the right angled triangle weirdly. Shows how important drawing a good diagram is.
    Offline

    3
    ReputationRep:
    (Original post by Palette)
    I spent age doing a relatively simple trigonometry question as I mislabelled 6\cos \theta and 6\sin \theta because I drew the right angled triangle weirdly. Shows how important drawing a good diagram is.
    Just label theta onto the other angle and you're good, if you mixed up the sides with those labels

    (pls tell me you didn't label the hypotenuse as one of those... :facepalm:)
    Offline

    2
    ReputationRep:
    I've been to Edexcel's page for the AEA award. The page is poorly set and there is no information of when the next tests are to be sat(or previous dates). I just finished learning the C3 and C4 , I know that the paper tests/advances skills in C1-C4. Do you have to pay to sit the paper like you do for STEP. Around what time of the year are the papers sat?
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by RDKGames)
    Just label theta onto the other angle and you're good, if you mixed up the sides with those labels

    (pls tell me you didn't label the hypotenuse as one of those... :facepalm:)
    The hypotenuse was 6; I just wrote 6\cos \theta where I was supposed to have written 6\sin\theta and vice versa. It was a Madas C2 paper, which was interesting (some questions were of normal difficulty while others were truly fiendish).
    Offline

    3
    ReputationRep:
    (Original post by Palette)
    The hypotenuse was 6; I just wrote 6\cos \theta where I was supposed to have written 6\sin\theta and vice versa. It was a Madas C2 paper, which was interesting (some questions were of normal difficulty while others were truly fiendish).
    Yeah just label the other angle as theta instead then rather than cross out the side lengths haha. Link the paper? I'm bored
    Offline

    3
    ReputationRep:
    (Original post by Dynamic_Vicz)
    I've been to Edexcel's page for the AEA award. The page is poorly set and there is no information of when the next tests are to be sat(or previous dates). I just finished learning the C3 and C4 , I know that the paper tests/advances skills in C1-C4. Do you have to pay to sit the paper like you do for STEP. Around what time of the year are the papers sat?
    Yes, you need to pay. You need to sit them in June.
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by RDKGames)
    Yeah just label the other angle as theta instead then rather than cross out the side lengths haha. Link the paper? I'm bored
    http://madasmaths.com/archive/iygb_p...apers/c2_t.pdf

    Q5, rather simple as long as you draw a good diagram.
    Offline

    2
    ReputationRep:
    1)  f(x)= (x^{2}-3x) / (x+1)
    I worked out f '(x) as  (x^{2}+2x-3) / (x+1)^{2}
    I'm stuck on how to work out the values of x for which f(x) is decreasing.

    2) Differentiate x / \sqrt {x+1}
    I rearranged it to  x(x+1)^{-1/2} and differentiated it as  -x /  2(x+1)^{3/2}
    The book's answer is  x+2 / 2(x+1)^{3/2}
    Online

    3
    ReputationRep:
    (Original post by osayukiigbinoba)
    1)  f(x)= (x^{2}-3x) / (x+1)
    I worked out f '(x) as  (x^{2}+2x-3) / (x+1)^{2}
    I'm stuck on how to work out the values of x for which f(x) is decreasing.

    2) Differentiate x / \sqrt {x+1}
    I rearranged it to  x(x+1)^{-1/2} and differentiated it as  -x /  2(x+1)^{3/2}
    The book's answer is  x+2 / 2(x+1)^{3/2}
    1. What is the definition of a decreasing function?

    2. This one is icky as there's a lot of rearranging going on but the book is definitely right. Please show your working
    Offline

    2
    ReputationRep:
    (Original post by SeanFM)
    1. What is the definition of a decreasing function?

    2. This one is icky as there's a lot of rearranging going on but the book is definitely right. Please show your working
    Thank you for replying.
    1. A decreasing function is when dy/dx < 0
    2. x(x+1)^-1/2
    Then I used the rule (ax+b)^n =an(ax+b)^n-1 because I couldn't get the right answer with the quotient rule either
    dy/dx = -1/2x(x+1)^{3/2}
    =  -x/ 2(x+1)^{3/2}
    Online

    3
    ReputationRep:
    (Original post by osayukiigbinoba)
    Thank you for replying.
    1. A decreasing function is when dy/dx < 0
    2. x(x+1)^-1/2
    Then I used the rule (ax+b)^n =an(ax+b)^n-1 because I couldn't get the right answer with the quotient rule either
    dy/dx = -1/2x(x+1)^{3/2}
    =  -x/ 2(x+1)^{3/2}
    So that should help you with question 1

    You can't do that when you have two functions multiplied by eachother (in this case x and (x+1)^(-1/2). You can use the product rule or the quotient rule.
    Offline

    2
    ReputationRep:
    (Original post by SeanFM)
    So that should help you with question 1

    You can't do that when you have two functions multiplied by eachother (in this case x and (x+1)^(-1/2). You can use the product rule or the quotient rule.
    I tried using the quotient rule but I'm not sure how to simplify this
     (x+1)^{1/2} - 1/2(x+1)^{-1/2}(x) / (x+1)
    Online

    3
    ReputationRep:
    (Original post by osayukiigbinoba)
    I tried using the quotient rule but I'm not sure how to simplify this
     (x+1)^{1/2} - 1/2(x+1)^{-1/2}(x) / (x+1)
    Brilliant, so you've applied the rule correctly - it's the most tricky part, the simplifying, that you just need to do.

    It's difficult to know what you want the simplified version to look like, but ideally you want no fractional powers in the numerator (after combining the two fractions) so you can multiply by the most appropriate numbers (eg if you had (x+1)^(1/2) and (x+1)^(-1/2) in the numerator then it would make sense to multiply both by (x+1)^(1/2) (this gets rid of both fractional powers) and move the thing you multiplied to the denominator.
 
 
 
Write a reply… Reply
Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: November 26, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Today on TSR
Poll
Would you rather have...?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

Equations

How to use LaTex

Writing equations the easy way

Student revising

Study habits of A* students

Top tips from students who have already aced their exams

Study Planner

Create your own Study Planner

Never miss a deadline again

Polling station sign

Thinking about a maths degree?

Chat with other maths applicants

Can you help? Study help unanswered threads

Groups associated with this forum:

View associated groups
Study resources

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.