Results 1 to 6 of 6

Math Help - Solving Exponential Equations

  1. #1
    Member
    Joined
    Sep 2009
    Posts
    181

    Solving Exponential Equations

    Hello,

    I'm a new user and I was hoping someone can help me with this problem?

    Edit: sorry I attached the wrong problem, it's actually:

    x^2e^x+xe^2-e^x=0

    hope this is clear

    Thanks!
    Attached Thumbnails Attached Thumbnails Solving Exponential Equations-math2.bmp  
    Last edited by l flipboi l; September 26th 2009 at 01:06 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Grandad's Avatar
    Joined
    Dec 2008
    From
    South Coast of England
    Posts
    2,570
    Thanks
    1
    Hello l flipboi l

    Welcome to Math Help Forum!
    Quote Originally Posted by l flipboi l View Post
    Hello,

    I'm a new user and I was hoping someone can help me with this problem?

    Sorry for the "crappy" illustration
    Solving Exponential Equations-math2.bmp
    [IMG]file:///Users/Mark/Library/Caches/TemporaryItems/moz-screenshot.png[/IMG][IMG]file:///Users/Mark/Library/Caches/TemporaryItems/moz-screenshot-1.png[/IMG]
    Divide through by a factor e^2. Then use the quadratic formula on the resulting equation: x^2+x-1=0.

    Grandad

    PS I answered your original question.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Flow Master
    mr fantastic's Avatar
    Joined
    Dec 2007
    From
    Zeitgeist
    Posts
    16,948
    Thanks
    5
    Quote Originally Posted by l flipboi l View Post
    Hello,

    I'm a new user and I was hoping someone can help me with this problem?

    Edit: sorry I attached the wrong problem, it's actually:

    x^2e^x+xe^2-e^x=0

    hope this is clear

    Thanks!
    I doubt an algebraic solution can be found using elementary functions. Please state the entire question from which the equation has come from.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Sep 2009
    Posts
    181
    Sorry I keep messing up, the equation is:

    x^2e^x+xe^x-e^x=0

    What's confusing me is the e^x, I can't seem to get anywhere near a solution

    Thanks,
    -Mark
    Follow Math Help Forum on Facebook and Google+

  5. #5
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by l flipboi l View Post
    Sorry I keep messing up, the equation is:

    x^2e^x+xe^x-e^x=0

    What's confusing me is the e^x, I can't seem to get anywhere near a solution

    Thanks,
    -Mark
    Quote Originally Posted by Grandad View Post

    Divide through by a factor e^2. Then use the quadratic formula on the resulting equation: x^2+x-1=0.
    Grandad already answered this

    To elaborate you can factor out e^x as it's a common factor:

    x^2e^x+xe^x-e^x= e^x(x^2+x-1) = 0

    Dividing through by e^x (this is allowed because for real x: e^x > 0) gives x^2+x-1 = 0

    Use the quadratic formula to solve for x
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Member
    Joined
    Sep 2009
    Posts
    181
    Quote Originally Posted by e^(i*pi) View Post
    Grandad already answered this

    To elaborate you can factor out e^x as it's a common factor:

    x^2e^x+xe^x-e^x= e^x(x^2+x-1) = 0

    Dividing through by e^x (this is allowed because for real x: e^x > 0) gives x^2+x-1 = 0

    Use the quadratic formula to solve for x
    ahhh yes! Thanks everyone for helping out, it makes alot more sense now.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Solving Exponential Equations
    Posted in the Algebra Forum
    Replies: 2
    Last Post: February 25th 2011, 03:29 PM
  2. Solving exponential equations
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: June 20th 2010, 05:20 AM
  3. Please help, solving exponential equations
    Posted in the Algebra Forum
    Replies: 3
    Last Post: February 10th 2010, 05:59 PM
  4. Solving Exponential Equations
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: April 23rd 2009, 02:33 AM
  5. need help on solving exponential equations!
    Posted in the Algebra Forum
    Replies: 1
    Last Post: November 12th 2007, 08:33 PM

Search Tags


/mathhelpforum @mathhelpforum