1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Pulling out -1 from denominator?

  1. Nov 16, 2007 #1
    I know this might seem trivial but I've never had a teacher cover this even though I've had the whole "factor out -1 from numerator " class.

    I was thinking of the cases but I haven't found a contradiction to:


    so is this always true?
  2. jcsd
  3. Nov 16, 2007 #2
    Obviously. After all (-x)/y=x/(-y)=-(x/y).
  4. Nov 16, 2007 #3


    User Avatar
    Science Advisor
    Homework Helper

    It's true. It's a special case of

  5. Nov 16, 2007 #4
    I've always wondered about that...
    for some reason no teacher I've had has ever done that manipulation.
  6. Nov 17, 2007 #5


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member
    Dearly Missed

    You might try to prove the following statements:
    [tex]\frac{1}{1}=1, \frac{1}{(-1)}=(-1)*\frac{1}{1}=(-1)[/tex]
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook