Results 1 to 2 of 2
Like Tree1Thanks
  • 1 Post By HallsofIvy

Thread: The inverse tan function is not matching actual angle. Why?

  1. #1
    Newbie
    Joined
    Mar 2018
    From
    Indiana
    Posts
    1

    Thumbs down The inverse tan function is not matching actual angle. Why?

    I have been using atn(1/6) for our standard tapered ball joint angles in 3D CAD. All derivations and definitions of the function say it should give me the angle. It's close, but when I force a 1:6 ratio angle it results in an angle of 9.527283˚. atn(1/6) yields 9.462322˚ Can anyone explain why there is a difference? Using a calculator yields the same thing as function in CAD. The difference is enough for our tapers not to seat correctly. The black dimensions are driving dimensions and the grey dimensions are resultants. The "Σ" indicates where the atn() function is being used. arctan should give me the same angle as a 1:6 triangle. (shown below)



    Forced 1:6 ratio to find actual angle


    The inverse tan function is not matching actual angle.  Why?-forced1-6.jpg
    Used arctan(1/6) to find side length
    The inverse tan function is not matching actual angle.  Why?-functiondriven1-6.jpg
    Attached Thumbnails Attached Thumbnails The inverse tan function is not matching actual angle.  Why?-atn-.jpg   The inverse tan function is not matching actual angle.  Why?-atn-_2.jpg  
    Last edited by eaton3420; Mar 28th 2018 at 04:51 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor

    Joined
    Apr 2005
    Posts
    19,793
    Thanks
    3035

    Re: The inverse tan function is not matching actual angle. Why?

    What do you mean by "force a ratio 1:6 angle" and how did that give you "9.527283˚"?
    Thanks from topsquark
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Replies: 0
    Last Post: Aug 18th 2017, 10:48 PM
  2. Replies: 2
    Last Post: Mar 16th 2013, 12:38 AM
  3. Replies: 6
    Last Post: Oct 23rd 2009, 03:07 AM
  4. Replies: 2
    Last Post: Sep 22nd 2009, 08:29 PM
  5. Formular, matching function input to output
    Posted in the Advanced Algebra Forum
    Replies: 4
    Last Post: Mar 29th 2008, 08:56 AM

Search Tags


/mathhelpforum @mathhelpforum