Results 1 to 4 of 4

Math Help - Logarithmic function

  1. #1
    Member
    Joined
    Oct 2009
    Posts
    229

    Logarithmic function

    Deriving 4x^3 + ln y^2 + 2y = 2x

    I think the first step is; 12x^2 + 1 / y^2 + and here is where I'm stuck. What is the derivative of the 2y and 2x?
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    Joined
    Jun 2009
    From
    United States
    Posts
    676
    Thanks
    19
    Quote Originally Posted by Archduke01 View Post
    Deriving 4x^3 + ln y^2 + 2y = 2x

    I think the first step is; 12x^2 + 1 / y^2 + and here is where I'm stuck. What is the derivative of the 2y and 2x?
    You have to use implicit differentiation. This should be easy, I think it is the ln(y^2) term that is confusing you.

    One of the properties of logarithms allows you to write:

    ln(y^2)=2ln(y)

    Use the chain rule to differentiation this:

    2\frac{d}{dx}ln(y)=\frac{2}{y}\frac{dy}{dx}

    That should help.
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Member
    Joined
    Oct 2009
    Posts
    229
    Quote Originally Posted by adkinsjr View Post
    You have to use implicit differentiation. This should be easy, I think it is the ln(y^2) term that is confusing you.

    One of the properties of logarithms allows you to write:

    ln(y^2)=2ln(y)

    Use the chain rule to differentiation this:

    2\frac{d}{dx}ln(y)=\frac{2}{y}\frac{dy}{dx}

    That should help.
    What does the 2y and the 2x become?
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Member
    Joined
    Oct 2009
    Posts
    229
    Quote Originally Posted by Archduke01 View Post
    What does the 2y and the 2x become?
    Does the 2y become 2yy'? What does the 2x become?
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Logarithmic function help
    Posted in the Pre-Calculus Forum
    Replies: 2
    Last Post: March 9th 2011, 03:12 AM
  2. Logarithmic function help
    Posted in the Pre-Calculus Forum
    Replies: 3
    Last Post: April 26th 2010, 01:15 PM
  3. logarithmic function
    Posted in the Differential Geometry Forum
    Replies: 1
    Last Post: April 17th 2010, 12:19 AM
  4. logarithmic function
    Posted in the Algebra Forum
    Replies: 5
    Last Post: September 27th 2009, 08:13 PM
  5. Logarithmic function
    Posted in the Calculus Forum
    Replies: 2
    Last Post: January 30th 2009, 06:15 PM

Search Tags


/mathhelpforum @mathhelpforum