Results 1 to 2 of 2

Math Help - Finding the partial derivative I think

  1. #1
    Newbie
    Joined
    Apr 2010
    Posts
    6

    Finding the partial derivative I think

    I think I'm supposed to find the partial derivative of the equation with respect to x and then with respect to y, right?

    The Problem is...

    Find the slope of the line that is parallel to the (a)xz-plane (b)yz-plane and tangent to the surface z=xln(x+y^2) at the point P(e,0,e)

    I just don't know how to find the partial derivatives of z=xln(x+y^2)
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,830
    Thanks
    123
    Quote Originally Posted by ghow90 View Post
    I think I'm supposed to find the partial derivative of the equation with respect to x and then with respect to y, right?

    The Problem is...

    Find the slope of the line that is parallel to the (a)xz-plane (b)yz-plane and tangent to the surface z=xln(x+y^2) at the point P(e,0,e)

    I just don't know how to find the partial derivatives of z=xln(x+y^2)
    Differentiate z(x,y) wrt x while considering y as a constant:

    Use the product rule: \frac{\partial z}{\partial x} = \ln(x+y^2) \cdot 1 + x \cdot  \frac1{x+y^2} \cdot 1 = \ln(x+y^2)+\frac x{x+y^2}

    Differentiate z(x,y) wrt y while considering x as a constant:

    Keep in mind: x is a constant factor here. Use the chain rule: \frac{\partial z}{\partial y} =  x \cdot  \frac1{x+y^2} \cdot 2y = \frac{2 x y}{x+y^2}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Derivative of arctan in a partial derivative
    Posted in the Calculus Forum
    Replies: 3
    Last Post: September 12th 2010, 01:52 PM
  2. Replies: 6
    Last Post: July 23rd 2010, 12:36 PM
  3. Second partial derivative?
    Posted in the Calculus Forum
    Replies: 9
    Last Post: October 3rd 2009, 07:21 AM
  4. Replies: 4
    Last Post: March 21st 2009, 10:00 PM
  5. partial derivative and finding an equation
    Posted in the Calculus Forum
    Replies: 2
    Last Post: March 9th 2009, 11:47 AM

Search Tags


/mathhelpforum @mathhelpforum