Find the semiaxes of the ellipse in which the plane meets the cylinder .
Have you visualised the plane and the cylinder? And their intersection? Then check semi axes at Ellipse - Wikipedia, the free encyclopedia and just find how far the intersection is from the origin, along the y axis, and along the line z = x in the x,z plane.
If visualising is the problem, do say.
The parametric equations of the cylinder are:
The square of the distance from the center of the ellipse to any point of is:
Easily you can find the maximum and the minimum absolute, of . The semi-axes are and .
Fernando Revilla
Yes, of course I meant ellipse.
Using your method, I get the semi-major axis as and semi-minor axis as .
Right.
Fernando Revilla