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: Modulus Function

  1. Feb 13, 2010 #1
    Okay, when I enter into the calculator sqrt(x^2) it equals |x|. Since when? I thought sqrt(x^2) equals x and then when you go to sketch it, it will be a positive diagonal line through the origin whereas |x| is a reflection at the origin.
  2. jcsd
  3. Feb 14, 2010 #2
    A number squared is always positive. So if you plug in -10 you get sqrt(100) which is 10.
    When you cancel out the square and the square root in a problem you do that because you're looking for the principle root aka the positive one.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook