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Math Help - Ok then, here's a tricky one.

  1. #1
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    Ok then, here's a tricky one.

    Find an equation for the surface consisting of all points P for which the distance from P to the x-axis is twice the distance from P to the yz-plane. Identify the surface.

    I get that the surface is a cone, but maybe my graph is off.
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  2. #2
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    Quote Originally Posted by Undefdisfigure View Post
    Find an equation for the surface consisting of all points P for which the distance from P to the x-axis is twice the distance from P to the yz-plane. Identify the surface.

    I get that the surface is a cone, but maybe my graph is off.
    The distance from x-axis to (x,y,z) is given by \sqrt{y^2+z^2}. The distance from (x,y,z) to yz-plane is given by |x|. Thus, we want \sqrt{x^2+y^2} = 2|x|. And this is a double cone because of the presence of an absolute value.
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