Results 1 to 3 of 3

Math Help - Help again

  1. #1
    Newbie
    Joined
    Jul 2008
    Posts
    7

    Help again

    f(x)= (x)/(2x+1)

    then

    f^-1(x) would =
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Member
    Joined
    Jul 2008
    Posts
    78
    Inverse of f(x)={\dfrac{x}{2x+1}}

    y = {\dfrac{x}{2x+1}}

    Switch the x and y variables,
    x={\dfrac{y}{2y+1}}

    Solve for y (I'll leave the algebra work to you),
    y={-\dfrac{x}{2x-1}}

    So, f^{-1}(x)={-\dfrac{x}{2x-1}}.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Senior Member nikhil's Avatar
    Joined
    Jun 2008
    Posts
    287
    Quote Originally Posted by andymana View Post
    f(x)= (x)/(2x+1)

    then

    f^-1(x) would =
    Let f(x)=y= (x)/(2x+1)
    2xy+y=x
    x(2y-1)=-y
    x=y/(1-2y)
    therfor
    f^-1(x)=x/(1-2x)
    Follow Math Help Forum on Facebook and Google+


/mathhelpforum @mathhelpforum