Turn on thread page Beta
    • Thread Starter
    Offline

    15
    ReputationRep:
    so the step which says that \sqrt3 is a rational in lowest terms i think i understand it to mean that no matter what a and b are, provided there is a common factor you will always come back to "lowest terms" am i right of have i still dun goofed?
    Offline

    12
    ReputationRep:
    (Original post by will'o'wisp2)
    so the step which says that \sqrt3 is a rational in lowest terms i think i understand it to mean that no matter what a and b are, provided there is a common factor you will always come back to "lowest terms" am i right of have i still dun goofed?
    The way you say this makes me think that you have already been talking about it on another thread - if so, I haven't seen that, so I'm not sure exactly what you mean.

    But the idea is that you start off assuming that root 3 is a fraction in its lowest terms, so something like a/b where a and b have no common factors. You then do a series of steps that shows that a and b actually do have a common factor, contradicting your assumption, and therefore proving that root 3 can't be a fraction after all.

    Is this what you are asking, or is it something more specific?
    • Thread Starter
    Offline

    15
    ReputationRep:
    (Original post by Pangol)
    The way you say this makes me think that you have already been talking about it on another thread - if so, I haven't seen that, so I'm not sure exactly what you mean.

    But the idea is that you start off assuming that root 3 is a fraction in its lowest terms, so something like a/b where a and b have no common factors. You then do a series of steps that shows that a and b actually do have a common factor, contradicting your assumption, and therefore proving that root 3 can't be a fraction after all.

    Is this what you are asking, or is it something more specific?
    This, cus i didn't understand what lowest terms meant and why it was important, but i understand the method to do a contradiction proof but i just can't do it lol.

    So what it's the same thing then? no common factors and lowest terms?
    Offline

    12
    ReputationRep:
    (Original post by will'o'wisp2)
    This, cus i didn't understand what lowest terms meant and why it was important, but i understand the method to do a contradiction proof but i just can't do it lol.

    So what it's the same thing then? no common factors and lowest terms?
    Yes. 4/10 is not in the lowest terms, but 2/5 is.
    • Community Assistant
    • Study Helper
    Offline

    20
    ReputationRep:
    Community Assistant
    Study Helper
    (Original post by will'o'wisp2)
    This, cus i didn't understand what lowest terms meant and why it was important, but i understand the method to do a contradiction proof but i just can't do it lol.

    So what it's the same thing then? no common factors and lowest terms?
    Any number that is rational can be written as a fraction in its lowest terms. E.g. 0.2 is rational and you can write it as 2/10 and 1/5 in its lowest terms.

    If you prove that it is impossible to write root 3 as a fraction in its lowest terms then it can't be rational.
    • Thread Starter
    Offline

    15
    ReputationRep:
    (Original post by Pangol)
    Yes. 4/10 is not in the lowest terms, but 2/5 is.
    (Original post by Notnek)
    Any number that is rational can be written as a fraction in its lowest terms. E.g. 0.2 is rational and you can write it as 2/10 and 1/5 in its lowest terms.

    If you prove that it is impossible to write root 3 as a fraction in its lowest terms then it can't be rational.
    time to add this to my notes, thank you both
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 7, 2017
Poll
Do you think parents should charge rent?
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.