Results 1 to 4 of 4

Math Help - Absolute Vaule

  1. #1
    Junior Member
    Joined
    Jul 2011
    Posts
    61

    Absolute Vaule

    1. \sqrt[4]{8x^5}

    2|x|\sqrt{x}

    2. \sqrt{49x^6}

    7|x^3| or |7x^3|? which one is valid?

    3. \sqrt{x^3}

    |x|\sqrt{x}?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member
    Joined
    Jul 2011
    Posts
    61

    Re: Absolute Vaule

    How do you use absolute value for radicals?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jul 2011
    From
    .
    Posts
    17

    Re: Absolute Vaule

    Hi, are you working in \mathbb{R}? If so,
    |x|\sqrt{x}=x\sqrt{x} because the domain of \sqrt{x} is \mathbb{R}^+\cup{}\left\{0\right\}
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5

    Re: Absolute Vaule

    Quote Originally Posted by theloser View Post
    [snip]
    2. \sqrt{49x^6}

    7|x^3| or |7x^3|? which one is valid?

    [snip]
    Both. But obviously the first is simpler.

    And you should note that:

    1. the domain of \sqrt{x^n} is x \geq 0 if n is odd (why?) and so |x | = x under such circumstances.

    2. the domain of \sqrt{x^n} is R if n is even (why?).
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 5
    Last Post: June 22nd 2010, 05:44 PM
  2. Replies: 8
    Last Post: May 23rd 2010, 11:59 PM
  3. finding absolute maximum and absolute minimum
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 15th 2009, 05:22 PM
  4. Replies: 2
    Last Post: November 8th 2009, 02:52 PM
  5. Replies: 2
    Last Post: September 7th 2007, 09:23 AM

Search Tags


/mathhelpforum @mathhelpforum