Results 1 to 5 of 5

Math Help - inverse function problem

  1. #1
    Junior Member
    Joined
    Aug 2010
    Posts
    41

    inverse function problem

    Could someone explain how to find the inverse function of g(x)=(e^x)-4?

    Thanks,
    Alex
    Follow Math Help Forum on Facebook and Google+

  2. #2
    A Plied Mathematician
    Joined
    Jun 2010
    From
    CT, USA
    Posts
    6,318
    Thanks
    4
    Awards
    2
    Do you know the general procedure? What ideas have you had so far?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Aug 2010
    Posts
    21
    Quote Originally Posted by juventinoalex View Post
    Could someone explain how to find the inverse function of g(x)=(e^x)-4?

    Thanks,
    Alex
    First change g(x) to y=
    y=e^{x}-4
    solve for x, and then switch the x and y terms
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Junior Member
    Joined
    Aug 2010
    Posts
    41
    Yes, i did that up to the solve for x part. I just did a problem where the x wasn't an exponent but that part has me kind of confused.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    MHF Contributor

    Joined
    Apr 2005
    Posts
    15,373
    Thanks
    1315
    So what, exactly have you done? Did you get to e^x= y+ 4?

    Do you know that the inverse to e^x is ln(x)?

    Here's another way of looking at it: f(x)= e^x- 4 basically tells you to do two things to x to evaluate the function: first take the exponential, then subtract 4. To find the inverse do the opposite things in the opposite order. Since the last thing you do in evaluating the function is "subtract 4", the first thing you do in finding the inverse is "add 4". Since the first thing you do in evaluating the function is take the exponential, the last ting you do in finding the inverse is the opposite of that. What function is the inverse to e^x again?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. inverse function problem
    Posted in the Algebra Forum
    Replies: 3
    Last Post: December 16th 2011, 04:12 AM
  2. Inverse Function Problem
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: November 8th 2010, 05:22 AM
  3. Inverse Function Problem
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: October 27th 2010, 04:08 AM
  4. Inverse function problem
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: January 24th 2010, 01:06 PM
  5. Inverse function problem
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: September 12th 2009, 06:29 PM

Search Tags


/mathhelpforum @mathhelpforum