Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    10
    ReputationRep:
    someone help me with c2 differentiation, I dont understand it with shapes
    • Community Assistant
    Offline

    17
    ReputationRep:
    Hello I've moved this to maths for you.

    Could you post an example of a question you are struggling with?
    • Thread Starter
    Offline

    10
    ReputationRep:
    (Original post by rayquaza17)
    Hello I've moved this to maths for you.

    Could you post an example of a question you are struggling with?

    for example if you have a look at the edexcel june 2014 c2 paper all of question 10.

    I really do not understand any of it

    please help!
    • TSR Support Team
    • Study Helper
    Offline

    20
    ReputationRep:
    (Original post by Mr revision)
    for example if you have a look at the edexcel june 2014 c2 paper all of question 10.

    I really do not understand any of it

    please help!
    So others don't have to find the question, here's the paper:
    http://qualifications.pearson.com/co...-June-2014.pdf

    Please post a link to the question in future threads.

    So starting with a), how do you work out the volume of a prism? Please post your thoughts and any working that you have done.
    Offline

    18
    ReputationRep:
    (Original post by Mr revision)
    for example if you have a look at the edexcel june 2014 c2 paper all of question 10.

    I really do not understand any of it

    please help!
    You use the relationship between an area and a volume
    (which it gives as 9600cm^3)

    take the area of the trapezium ((h(a+b))/2) which for this question:
    a(x) = ((4x(9x+6x))/2) = 30x^2

    the volume is the area * length (y) so,
    y * a(x) = 9600cm^3

    therefore

    y = 9600cm^3/a(x) = 9600cm^3/30x^2 = 320/x^2
    --------------------------------------------------------------------
    surface area:
    you take:
    S = 2a(x) + y(6x) + y(9x) + y(4x) + y(5x)
    = 60x^2 +y(24x)
    = 60x^2 + (320/x^2) * (24x)
    = 60x^2 + (7680/x)
    ---------------------------------------------------------------------
    finding minimum of S (when dS/dx = 0)
    ---------------------------------------------------------------------
    you can justify it's a minimum if S'' is positive (>0) for the value of S you found in 10 (c)
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Did TEF Bronze Award affect your UCAS choices?
    Useful resources

    Make your revision easier

    Maths

    Maths Forum posting guidelines

    Not sure where to post? Read the updated guidelines here

    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
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • 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.