Osgood, William F. (William Fogg), 1864-1943, Graustein, William C. (William Caspar), 1888-1941, joint author · New York : The Macmillan Company · leaf 583
xis are equal and similarly-placed parabolas. • 3. Prove that a hyperbolic paraboloid has no elliptic sec-tions, that sections by two parallel planes cutting the axesare hyperbolas, one of which is similar and similarly placedeither to the other or to the conjugate of the other, and thatsections by… … Fig. 9 by a plane M passing through the axis of y. The section is anellipse, one of whose axes is always the mean axis, 26, of the ellipsoid, no matter how M is situ-ated. When M^ starting from the(x, 2/)-plane, rotates in either direc-tion into coincidence with the (y, zyplane, the second axis of…
