Turn on thread page Beta
    • Thread Starter
    Offline

    14
    ReputationRep:
    Hi, could anybody help me with this problem attached? I was thinking about using proof by contradiction but I honestly no idea how or where to start.
    Attached Images
      
    Offline

    12
    ReputationRep:
    (Original post by Hiling99)
    Hi, could anybody help me with this problem attached? I was thinking about using proof by contradiction but I honestly no idea how or where to start.
    The fact that there is an n1 such that n1 > x is just a restatement of the statement before the question (I assume that this is Archimedes' Theorem). For the other part, consider what this same statement tells you about -x.
    • Thread Starter
    Offline

    14
    ReputationRep:
    Yeah that is Archimedes' Theorem, sorry I forgot to mention that.

    So if you consider -x then would that just mean For every x ϵ ℝ there exists n ϵ ℕ such that -x>-n?
    Offline

    12
    ReputationRep:
    (Original post by Hiling99)
    Yeah that is Archimedes' Theorem, sorry I forgot to mention that.

    So if you consider -x then would that just mean For every x ϵ ℝ there exists n ϵ ℕ such that -x>-n?
    I wouldn't try and rewrite Archimdes' Theorem. I would just use the fact that -x is still a real number. Use -x as the real number in the theorem.
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 15, 2017
Poll
Is the Big Bang theory correct?
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.