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!

Homework Help: Limit question

  1. May 21, 2016 #1
    • Member warned that the homework template is required
  2. jcsd
  3. May 21, 2016 #2

    andrewkirk

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    It's almost right. The only problem is that ##k## may be negative. So multiplying the inequality by ##k## will change direction of the inequality, which will prevent reaching the conclusion.

    Two ways to get around this are:

    1. Do three separate cases, for k positive, negative and zero respectively; or
    2. Multiply by ##|k|## instead.

    2 is quicker, but you'll need to insert a few careful steps around where you multiply by ##|k|## to ensure that each one is valid.
     
  4. May 21, 2016 #3
    Thank you very much!
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted