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

    14
    ReputationRep:
    Q 8 ii
    Name:  IMG_20130516_211351.jpg
Views: 79
Size:  218.5 KB


    a= -3/2
    n =16

    For the second part, you work out x = 0.001 and then plug it into the initial equation but surely that's not a good estimate since you're only using three terms?

    Mark scheme

    Name:  IMG_20130516_211814.jpg
Views: 60
Size:  268.0 KB
    • Political Ambassador
    Offline

    3
    ReputationRep:
    Political Ambassador
    (Original post by eggfriedrice)
    Q 8 ii
    Name:  IMG_20130516_211351.jpg
Views: 79
Size:  218.5 KB


    a= -3/2
    n =16

    For the second part, you work out x = 0.001 and then plug it into the initial equation but surely that's not a good estimate since you're only using three terms?

    Mark scheme

    Name:  IMG_20130516_211814.jpg
Views: 60
Size:  268.0 KB
    Notice that the question says 'for small values of x', i.e values that are close to zero.

    Notice that, if

    0<x<1

    then

    x^n \rightarrow 0 as n \rightarrow \infty

    So it's not a bad estimate despite the fact that you're only using 3 terms (the values of x must be really small!)

    Does that help?
    • Thread Starter
    Offline

    14
    ReputationRep:
    (Original post by Indeterminate)
    Notice that the question says 'for small values of x', i.e values that are close to zero.

    Notice that, if

    0<x<1

    then

    x^n \rightarrow 0 as n \rightarrow \infty

    So it's not a bad estimate despite the fact that you're only using 3 terms (the values of x must be really small!)

    Does that help?
    I half understand it haha but it's better than not understanding it at all, thanks. 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
    Would you like to hibernate through the winter months?
    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.