Results 1 to 5 of 5

Math Help - simultaneous equations involving e and ln.

  1. #1
    Junior Member
    Joined
    Nov 2007
    Posts
    33

    simultaneous equations involving e and ln.

    urgh, i dont even know where to start. any help would be much appreciated.

    i have written the power in brackets because i dont know how to make them superscript, sorry!

    solve to 2dp the following simultaneous equations.

    e(to the power of 2y) - x + 2 = 0
    ln(x+3) - 2y - 1 = 0

    thanks

    ps, the x+3 is not a power, its actually in brackets :P
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member FalconPUNCH!'s Avatar
    Joined
    Sep 2007
    From
    Daly City, CA
    Posts
    167
    While I may not be able to help you this moment because I have class in a couple of minutes I will help with the script

    e^{(2y)} - x + 2 = 0

      ln(x+3) - 2y - 1 = 0
    Follow Math Help Forum on Facebook and Google+

  3. #3
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,110
    Thanks
    2
    What's the hangup? This one solve directly. Why do you need to specify decimal places?

    From the second, y = (ln(x+3)-1)

    Substituting into the first: e^{ln(x+3)-1}\;-\;x\;+\;2\;=\;0

    Resolve that exponent and you are almost done!
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Nov 2007
    Posts
    33
    doesnt that result in cancelling out the x's though?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor
    Joined
    Aug 2007
    From
    USA
    Posts
    3,110
    Thanks
    2
    e^{ln(x+3)-1}\;=\;e^{ln(x+3)}e^{-1}\;=\;\frac{x+3}{e}

    Doesn't look like it. Let the notation help you. No need to guess.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Simultaneous Equations 4 variables, 4 equations
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: December 7th 2011, 04:06 PM
  2. [SOLVED] Simultaneous equations involving cos and sin
    Posted in the Trigonometry Forum
    Replies: 1
    Last Post: October 17th 2010, 04:18 AM
  3. Replies: 3
    Last Post: February 27th 2009, 07:05 PM
  4. Replies: 2
    Last Post: February 2nd 2009, 04:14 PM
  5. Replies: 2
    Last Post: August 7th 2008, 11:38 PM

Search Tags


/mathhelpforum @mathhelpforum