Turn on thread page Beta
    • Thread Starter
    Offline

    5
    ReputationRep:
    ..
    Offline

    20
    ReputationRep:
    you can say ((1 + i)/(1 - i)) = (ai + b)2 , where ai + b is what you are trying to find.

    now simplify, cross multiply & compare coefficients to find a & b
    Offline

    21
    ReputationRep:
    (Original post by jlf98)
    How would I put Root((1+i)/(1-i)) in the form x+iy.
    I multiplied the fraction by the conjugate of the denominator (1+i) to get root(i) then i dont know where to go from there?
    do you know what de moivres theorum is?
    Offline

    18
    ReputationRep:
    (Original post by bruh2132)
    do you know what de moivres theorum is?
    I wouldn't jump to use De Moivre's here considering that the OP hasn't mentioned their study level. I'd say an approach by comparing coefficients would likely be more accessible to the OP.
    Offline

    21
    ReputationRep:
    (Original post by _gcx)
    I wouldn't jump to use De Moivre's here considering that the OP hasn't mentioned their study level. I'd say an approach by comparing coefficients would likely be more accessible to the OP.
    yh I was just asking, if he did know about it it might have been easier
    • Thread Starter
    Offline

    5
    ReputationRep:
    yes would you say to approach the question using de moivres theorem ?
    Offline

    21
    ReputationRep:
    (Original post by jlf98)
    yes would you say to approach the question using de moivres theorem ?
    I would do it that way if you know how, since i can be written in the form cos(theta)+isin(theta), you can raise that to a power and put it in whatever form you want
    • Study Helper
    Offline

    16
    ReputationRep:
    Study Helper
    (Original post by jlf98)
    How would I put Root((1+i)/(1-i)) in the form x+iy.
    I multiplied the fraction by the conjugate of the denominator (1+i) to get root(i) then i dont know where to go from there?
    When you multiply top and bottom by 1+i you might want to leave the numerator as (1+i)^2 - you should see the answer straight away (N.B. you might think there could be 2 possible answers, but remember that the root sign indicates the principal square root)
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: October 15, 2017

University open days

  • University of East Anglia
    UEA Mini Open Day Undergraduate
    Fri, 23 Nov '18
  • Norwich University of the Arts
    Undergraduate Open Days Undergraduate
    Fri, 23 Nov '18
  • Edge Hill University
    All Faculties Undergraduate
    Sat, 24 Nov '18
Poll
Black Friday: Yay or Nay?
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

Equations

Best calculators for A level Maths

Tips on which model to get

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.