C2 help

Announcements
    • Thread Starter
    Offline

    2
    ReputationRep:
    3 - 75/x^2=0
    can somone help me solve this, its something i should be able to do but i cant get my mind around it.
    this is what i should get x=5
    Online

    3
    ReputationRep:
    (Original post by djmans)
    3 - 75/x^2=0
    can somone help me solve this, its something i should be able to do but i cant get my mind around it.
    this is what i should get x=5
    You could move the second term over to the right hand side to give

     3 = \frac{75}{x^2} and then try to get the x^2 on its own and work from there.
    Offline

    1
    ReputationRep:
    (Original post by SeanFM)
    You could move the second term over to the right hand side to give

     3 = \frac{75}{x^2} and then try to get the x^2 on its own and work from there.
    Ive got a problem if you could help mee too
    √ 7
    --------
    3-√ 7
    Simplifying in surds
    Online

    3
    ReputationRep:
    (Original post by harrxful)
    Ive got a problem if you could help mee too
    √ 7
    --------
    3-√ 7
    Simplifying in surds
    When you want to simplify a surd of that form, what do you usually tend to do with the denominator?
    Offline

    1
    ReputationRep:
    (Original post by SeanFM)
    When you want to simplify a surd of that form, what do you usually tend to do with the denominator?
    times all of it by the denominatior
    √ 7
    --------
    3-√7


    *
    √ 7
    ----
    √ 7
    Online

    3
    ReputationRep:
    (Original post by harrxful)
    times all of it by the denominatior
    √ 7
    --------
    3-√7


    *
    √ 7
    ----
    √ 7
    I know what you're trying to say but you actually have to rationalise it. Since the denominator is  3 - \sqrt7, \mathrm{you\ have\ to\ multiply\ it\ by} \frac{3 + \sqrt7}{3 + \sqrt7}
    Offline

    1
    ReputationRep:
    (Original post by SeanFM)
    I know what you're trying to say but you actually have to rationalise it. Since the denominator is  3 - \sqrt7, \mathrm{you\ have\ to\ multiply\ it\ by} \frac{3 + \sqrt7}{3 + \sqrt7}
    I spent like 5 minutes trying to analyse where I went wrong
    thanks man hopefully I can learn from that now
 
 
 
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: October 1, 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
Would you prefer to be told about sex by your:
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
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

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