Results 1 to 5 of 5

Math Help - the reciprocal identity..

  1. #1
    Junior Member
    Joined
    Jun 2010
    Posts
    47

    the reciprocal identity..


    There is the given. The instruction is to differentiate.


    Now my question is, can I do..





    ..by using the trigonometric reciprocal identity, in which it results to




    ??? Thanks!
    Attached Thumbnails Attached Thumbnails the reciprocal identity..-ans.jpg   the reciprocal identity..-rec.jpg   the reciprocal identity..-tan.jpg  
    Last edited by cutiemike1; August 29th 2010 at 05:17 PM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by cutiemike1 View Post

    There is the given. The instruction is to differentiate.


    Now my question is, can I do..





    ..by using the trigonometric reciprocal identity, in which it results to




    ??? Thanks!
    NO. \displaystyle \frac{1}{\tan^{-1}(4x)} \neq \cot^{-1}(4x). Do you realise that \tan^{-1}(4x) means the inverse tan function, NOT the reciprocal tan function.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Jun 2010
    Posts
    47
    Quote Originally Posted by mr fantastic View Post
    NO. \displaystyle \frac{1}{\tan^{-1}(4x)} \neq \cot^{-1}(4x). Do you realise that \tan^{-1}(4x) means the inverse tan function, NOT the reciprocal tan function.
    yeah! it boggles my mind, but I know it isn't right..

    but on the other hand is it possible to do it in QUOTIENT RULE??

    or what could be the correct procedure? may be you can show me the first step only then i will do the rest..include also the answer but not the solution so that i may compare it to what i will do..
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    skeeter's Avatar
    Joined
    Jun 2008
    From
    North Texas
    Posts
    11,697
    Thanks
    451
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Jun 2010
    Posts
    47
    alright! yeah!.. ) THANKS a LOT skeeter and mr. fantastic.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. reciprocal
    Posted in the Math Topics Forum
    Replies: 2
    Last Post: February 5th 2010, 09:11 AM
  2. reciprocal cm?
    Posted in the Calculus Forum
    Replies: 2
    Last Post: November 2nd 2009, 01:54 AM
  3. multiply by reciprocal
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 28th 2008, 09:49 AM
  4. reciprocal
    Posted in the Algebra Forum
    Replies: 1
    Last Post: September 22nd 2008, 03:47 PM
  5. If the reciprocal of x+1 is...
    Posted in the Algebra Forum
    Replies: 1
    Last Post: February 21st 2007, 04:39 PM

Search Tags


/mathhelpforum @mathhelpforum