Just one sec...
Hey! Sign in to get help with your study questionsNew here? Join for free to post

Can you simplyify both sides of the equal sign when working out intersection points?

Announcements Posted on
Take our short survey, £100 of Amazon vouchers to be won! 23-09-2016
    • Thread Starter
    Offline

    0
    ReputationRep:
    Would multiplying and dividing both side of an equation when working out intersection point of 2 curves change the points of intersection?
    Offline

    2
    ReputationRep:
    Never divide - factorise
    Make sure you don't add solutions when you multiply
    Other than that it's ok
    Offline

    2
    ReputationRep:
    Also if it's by a constant it's ok.
    Offline

    3
    ReputationRep:
    (Original post by TheAdviser101)
    Would multiplying and dividing both side of an equation when working out intersection point of 2 curves change the points of intersection?
    Do you have an example? Though as above, never divide by variables, factor them out instead.
    • Thread Starter
    Offline

    0
    ReputationRep:
    (Original post by RDKGames)
    Do you have an example? Though as above, never divide by variables, factor them out instead.
    9x^2 + 6x + 12 = 3x - 6

    So in this case if divide both graphs by 3 (take out a factor of 3), the points of intersection will be identical as the original? btw what do you mean by dividing by variables? Can you give an example. Thanks
    Offline

    3
    ReputationRep:
    (Original post by TheAdviser101)
    9x^2 + 6x + 12 = 3x - 6

    So in this case if divide both graphs by 3 (take out a factor of 3), the points of intersection will be identical as the original? btw what do you mean by dividing by variables? Can you give an example. Thanks
    Dividing and taking out a factor is not the same thing. Since 3 is a constant non-zero term you can freely divide by it and the quantity's will still remain equal, so yes the answer's will be the same.

    Dividing by variables would be something like dividing both sides by x like so: x^2=2x \Rightarrow x=2 (as x varies - hence a variable) which is wrong as you are losing a solution.
 
 
 
Write a reply…

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. Oops, you need to agree to our Ts&Cs to register
  2. Slide to join now Processing…

Updated: September 18, 2016
TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

Poll
Who will be the next permanent England boss?
Useful resources

Make your revision easier

Maths

Maths Forum posting guidelines

Not sure where to post? Read here first

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
Study resources

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

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