Results 1 to 8 of 8

Math Help - confused... fractions and indicies

  1. #1
    Junior Member
    Joined
    Oct 2008
    Posts
    50

    confused... fractions and indicies

    Simplify


    16^1/2/81^3/4


    i got the answer again but im not sure about the bottom half since i just cube rooted the 81 and wasnt sure what to do with the 4 part of it.... dont know if this is coincidently the right answer that i got...

    please explain the method, thanks!

    sorry i cant get the hang of the [tex] thing , its suppose to be 16^half all over (divided by) 81^three quarters
    Last edited by coyoteflare; January 8th 2009 at 09:37 AM. Reason: apologies
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Junior Member shinhidora's Avatar
    Joined
    Jun 2008
    Posts
    56
    Quote Originally Posted by coyoteflare View Post
    Simplify


    16^1/2/81^3/4


    i got the answer again but im not sure about the bottom half since i just cube rooted the 81 and wasnt sure what to do with the 4 part of it.... dont know if this is coincidently the right answer that i got...

    please explain the method, thanks!
    I don't get it... you mean...

    16 divided by 2 divided by 18^{3} divided by 4?

    Edit: Ow like this?

    \sqrt{16} = 16^{\frac{1}{2}}

    16^{\frac{1}{2}} = 4

    \sqrt[4]{81^{3}} = 81^{\frac{3}{4}}

    81^{\frac{3}{4}} = 27

    \frac{16^{\frac{1}{2}}}{81^{\frac{3}{4}}}= \frac{4}{27}
    Last edited by shinhidora; January 8th 2009 at 09:57 AM.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Oct 2008
    Posts
    50
    \frac{16^{1/2}}{81^{3/4}}



    16 to the power of a half divided by 81 to the power of three quarters

    i cant get the Latex to do it tooconfusing for me
    Last edited by mr fantastic; January 8th 2009 at 12:01 PM. Reason: Fixed the latex
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member shinhidora's Avatar
    Joined
    Jun 2008
    Posts
    56
    Quote Originally Posted by coyoteflare View Post
    [tex]{\frac{16^{\frac{1}{2}}}{81^{\frac{3}{4}}}



    16 to the power of a half divided by 81 to the power of three quarters

    i cant get the Latex to do it tooconfusing for me

    It isn't that hard

    In short, for your problem

    \frac{a}{b} = \frac{a}{b}
    a^{b} = a^{b}

    By the way, I edited my original post with the answers and stuff
    Follow Math Help Forum on Facebook and Google+

  5. #5
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by shinhidora View Post
    I don't get it... you mean...

    16 divided by 2 divided by 18^{3} divided by 4?

    Edit: Ow like this?

    \frac{16^{\frac{1}{2}}}{81^{\frac{3}{4}}}
    That's what I understood, too. Using radicals it would be

    \frac{\sqrt{16}}{(\sqrt[4]{81})^3}
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Junior Member shinhidora's Avatar
    Joined
    Jun 2008
    Posts
    56
    In general it's

    \sqrt[a]{n^{b}} = n^{\frac{b}{a}}


    This will make it more clear I guess
    Follow Math Help Forum on Facebook and Google+

  7. #7
    Junior Member
    Joined
    Oct 2008
    Posts
    50

    without soundign too stupid

    how is <br /> <br />
\sqrt[4]{81^{3}} = 81^{\frac{3}{4}}<br />
= 27?

    i do \sqrt[4]{81} then cube the answer and it coems out massive!?
    Follow Math Help Forum on Facebook and Google+

  8. #8
    A riddle wrapped in an enigma
    masters's Avatar
    Joined
    Jan 2008
    From
    Big Stone Gap, Virginia
    Posts
    2,551
    Thanks
    12
    Awards
    1
    Quote Originally Posted by coyoteflare View Post
    how is <br /> <br />
\sqrt[4]{81^{3}} = 81^{\frac{3}{4}}<br />
= 27?

    i do \sqrt[4]{81} then cube the answer and it coems out massive!?
    Hello coyote,

    The 4th root of 81 is 3.

    3 cubed = 27. Not too massive.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Confused about partial fractions integration
    Posted in the Calculus Forum
    Replies: 6
    Last Post: March 2nd 2011, 01:21 AM
  2. Indicies
    Posted in the Number Theory Forum
    Replies: 3
    Last Post: March 10th 2010, 11:36 AM
  3. Replies: 2
    Last Post: January 10th 2010, 08:45 AM
  4. Replies: 5
    Last Post: November 21st 2009, 07:28 PM
  5. Indicies
    Posted in the Algebra Forum
    Replies: 2
    Last Post: October 14th 2008, 12:13 PM

Search Tags


/mathhelpforum @mathhelpforum