1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Quadratic surface

  1. Dec 10, 2013 #1
    In equation z=y^2-x^2 when graphing the trace for y^2-x^2=k I see we have y=+-x for k=0 else y=+-sqrt(k+x^2) is there a simple way to graph this
  2. jcsd
  3. Dec 11, 2013 #2
    We'll to answer my own question I find it convenient to first take k=0 then we have y=+-x then taking k=1 and y=0 we have points (+-1,0) for k<0 then taking x=0 we have point (0,+-1) for k>0 now here we see that as y to +- infinity y will tend to the line y=+-x using lhopatols rule any thoughts here
  4. Dec 11, 2013 #3


    Staff: Mentor

    In addition to the horizontal cross sections you are plotting, it would be useful to plot the traces in the three coordinate planes. For example, in the y-z plane (when x = 0) you get z = y2, a parabola. In the x-z plane, you also get a parabola.
  5. Dec 11, 2013 #4
    Yes I am just interested in that particular trace is there's better way to graph it
  6. Dec 11, 2013 #5


    Staff: Mentor

    For y = ##\sqrt{x^2 + k}##, just plot some points. The graph of y = ##-\sqrt{x^2 + k}## is the reflection across the x-axis of the first one.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted

Similar Discussions: Quadratic surface
  1. Quadratic surface (Replies: 2)

  2. Quadratic surface (Replies: 2)

  3. Quadratic surfaces (Replies: 1)

  4. Quadratic surfaces (Replies: 3)