Results 1 to 3 of 3

Math Help - Finding an indefinite integral

  1. #1
    Junior Member
    Joined
    Jan 2010
    Posts
    72

    Finding an indefinite integral

    Find the integral of:

    [g'(x)] / [g(x)]^2


    I got as an anser:

    [g(x)] / 1/3[g(x)]^3

    ...but I'm not sure if I broke some kind of rules.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Senior Member
    Joined
    Nov 2009
    Posts
    263

    Smile

    Quote Originally Posted by WartonMorton View Post
    Find the integral of:

    [g'(x)] / [g(x)]^2


    I got as an anser:

    [g(x)] / 1/3[g(x)]^3

    ...but I'm not sure if I broke some kind of rules.
    hi warton,..
    i suggest you to use the substitution method

    \int \frac{g'(x)}{g^2(x)}~dx = \int \frac{~d(g(x))}{g^2(x)} = - \frac{1}{g(x)} + C
    Follow Math Help Forum on Facebook and Google+

  3. #3
    -1
    e^(i*pi)'s Avatar
    Joined
    Feb 2009
    From
    West Midlands, England
    Posts
    3,053
    Thanks
    1
    Quote Originally Posted by WartonMorton View Post
    Find the integral of:

    [g'(x)] / [g(x)]^2


    I got as an anser:

    [g(x)] / 1/3[g(x)]^3

    ...but I'm not sure if I broke some kind of rules.
    u = g(x) therefore du = g'(x) dx \: \: \rightarrow \: dx = \frac{du}{g'(x)}

    <br />
\int \frac{g'(x)}{u^2\,g'(x)}\,du = \int \frac{du}{u^2}

    = -\frac{1}{u}+C = -\frac{1}{g(x)}+C
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] finding indefinite integral without sub method
    Posted in the Calculus Forum
    Replies: 1
    Last Post: September 25th 2010, 12:42 PM
  2. Finding the indefinite integral
    Posted in the Calculus Forum
    Replies: 2
    Last Post: September 12th 2010, 01:27 PM
  3. finding the indefinite integral
    Posted in the Calculus Forum
    Replies: 4
    Last Post: January 26th 2010, 02:50 AM
  4. Finding Indefinite Integral
    Posted in the Calculus Forum
    Replies: 2
    Last Post: May 8th 2009, 06:24 AM
  5. Please help...Finding the indefinite Integral
    Posted in the Calculus Forum
    Replies: 4
    Last Post: April 16th 2008, 08:17 PM

Search Tags


/mathhelpforum @mathhelpforum