Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    15
    On the attached image.
    Attached Images
     
    Offline

    19
    ReputationRep:
    (Original post by EricPiphany)
    On the attached image.
    post the question and hopefully someone will help you
    • Thread Starter
    Offline

    15
    (Original post by TeeEm)
    post the question and hopefully someone will help you
    I've taken the second derivative of the first line, then substituted x = -1. For odd n, the left side is an integer and the right side is a fraction.
    Offline

    19
    ReputationRep:
    (Original post by EricPiphany)
    I've taken the second derivative of the first line, then substituted x = -1. For odd n, the left side is an integer and the right side is a fraction.
    hopefully one of the big guns will soon arrive
    Offline

    18
    ReputationRep:
    The mistake is your factorisation on the second line after subbing in x=-1.

    You can't factorise (-1)n out of the entire numerator because of the +2 at the end.
    Offline

    19
    ReputationRep:
    (Original post by justinawe)
    The mistake is your factorisation on the second line after subbing in x=-1.

    You can't factorise (-1)n out of the entire numerator because of the +2 at the end.
    An American comes to the rescue ...
    • Thread Starter
    Offline

    15
    (Original post by justinawe)
    The mistake is your factorisation on the second line after subbing in x=-1.

    You can't factorise (-1)n out of the entire numerator because of the +2 at the end.
    Thanks a lot for that
    • Thread Starter
    Offline

    15
    I was much too eager to factorise that (-1)^n out...
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: November 4, 2015
Poll
Do you agree with the proposed ban on plastic straws and cotton buds?
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

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

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