Results 1 to 2 of 2

Math Help - Find the equation of the normal

  1. #1
    Junior Member
    Joined
    Sep 2009
    Posts
    57

    Find the equation of the normal

    The tangent at P to the curve y=x^2 has gradient 3. Find the equation of the normal at P.

    The answer of this question is 12y=-4x+33

    Please help me with this question, please
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Jester's Avatar
    Joined
    Dec 2008
    From
    Conway AR
    Posts
    2,361
    Thanks
    39
    Quote Originally Posted by creatively12 View Post
    The tangent at P to the curve y=x^2 has gradient 3. Find the equation of the normal at P.

    The answer of this question is 12y=-4x+33

    Please help me with this question, please
    The slope of the tangent is given by \frac{dy}{dx} = 2x. If this is 3 then the x value is x = \frac{3}{2}. The normal has slope - \frac{1}{3}. The equation for this through \left( \frac{3}{2}, \frac{9}{4} \right) is

     <br />
y - \frac{9}{4} = - \frac{1}{3} \left(x- \frac{3}{2} \right)<br />

    and if you simplify you'll get the answer you give.
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. [SOLVED] Find the gradient of the normal
    Posted in the Calculus Forum
    Replies: 1
    Last Post: May 12th 2011, 06:39 AM
  2. Replies: 1
    Last Post: May 23rd 2010, 09:09 AM
  3. Replies: 3
    Last Post: December 29th 2009, 04:02 PM
  4. find the equation of the normal on the ellipse
    Posted in the Calculus Forum
    Replies: 1
    Last Post: November 30th 2009, 02:01 AM
  5. find normal of a cone
    Posted in the Calculus Forum
    Replies: 1
    Last Post: April 25th 2008, 04:01 PM

Search Tags


/mathhelpforum @mathhelpforum