Calculus Calculus Math Forum

 February 16th, 2009, 01:23 PM #1 Member   Joined: Feb 2009 Posts: 76 Thanks: 0 Quadratic surfaces Reduce the equation to one of the standard forms, classify the surface and sketch it. 4x^2 - 9y^2 + z^2 + 36 = 0 so... my work--> (4x^2 - 9y^2 + z^2 + 36 = 0) / 36 x^2 /9 - y^2 / 4 + z^2 /36 = -1 -x^2 /9 + y^2 / 4 - z^2 /36 = 1 I am not sure what to classify this surface. I think its an hyperboloid of Two sheets. but I am not sure how to sketch this
 February 17th, 2009, 04:40 AM #2 Senior Member   Joined: Dec 2008 Posts: 251 Thanks: 0 Re: Quadratic surfaces I just tried sketching it. It might be easier to scale the $x$ and $z$ axes down a bit.