Results 1 to 5 of 5

Math Help - Finding roots of an exponential equation with multiple base numbers

  1. #1
    Newbie
    Joined
    Apr 2009
    Posts
    3

    Finding roots of an exponential equation with multiple base numbers

    Hey everyone, first post.

    Just wondering if anyone can help me out with finding 'a' when the equation below is equal to 0


    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-2.jpg[/IMG][IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-3.jpg[/IMG](94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60



    Cheers
    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-1.jpg[/IMG]
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Like a stone-audioslave ADARSH's Avatar
    Joined
    Aug 2008
    From
    India
    Posts
    726
    Thanks
    2
    Quote Originally Posted by jvigar View Post
    Hey everyone, first post.

    Just wondering if anyone can help me out with finding 'a' when the equation below is equal to 0


    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-2.jpg[/IMG]

    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-3.jpg[/IMG]

    (94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60



    Cheers
    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot.jpg[/IMG]

    [IMG]file:///C:/Users/Jaiba/AppData/Local/Temp/moz-screenshot-1.jpg[/IMG]
    Welcome to the Forum

    See if you want of copy an image from another site write like this

    [img]image location [/img]

    you can get the location of image by right clicking on the image and than -"copy image location"
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Apr 2009
    Posts
    3
    sorry about that, I tried to paste directly from maple.

    The equation is,

    (94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60 = 0

    and I'm trying to find "a"

    many thanks

    Josh
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Grand Panjandrum
    Joined
    Nov 2005
    From
    someplace
    Posts
    14,972
    Thanks
    4
    Quote Originally Posted by jvigar View Post
    sorry about that, I tried to paste directly from maple.

    The equation is,

    (94-10^a)*10^a*ln10+(118-16^a)*16^a*ln16+(147-25^a)*25^a*ln25+(180-40^a)*40^a*ln40+(230-60^a)*60^a*ln60 = 0

    and I'm trying to find "a"

    many thanks

    Josh
    Ask Maple for a numerical solution. It should give a ~= 1.3674 for the positive root (I have not checked for negative roots)

    (you can't link to image files on your hard drive, they have to be on a machine that can been seen by the internet (such as an image hosting server), otherwise upload the image from the attachments dialog in the advanced editor)

    CB
    Last edited by CaptainBlack; April 23rd 2009 at 03:56 AM.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Newbie
    Joined
    Apr 2009
    Posts
    3
    Thanks, I must have done something wrong in maple.

    I ended up using newtons method in excel, and got the same value.

    Thanks again for all your help

    Josh
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Finding unknown base from equation
    Posted in the Algebra Forum
    Replies: 7
    Last Post: January 31st 2011, 09:36 PM
  2. Finding roots of complex numbers
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: August 25th 2010, 04:57 AM
  3. Replies: 1
    Last Post: June 29th 2010, 10:39 PM
  4. Finding roots of an exponential function
    Posted in the Calculus Forum
    Replies: 1
    Last Post: October 19th 2008, 03:39 PM
  5. Complex Numbers - Finding Roots
    Posted in the Trigonometry Forum
    Replies: 3
    Last Post: April 23rd 2007, 08:50 PM

Search Tags


/mathhelpforum @mathhelpforum