Aldis, W. Steadman (William Steadman), 1839-1928 · Cambridge [Eng.] Deighton, Bell, and co.; London, G. Bell and sons · leaf 58
parabola, the planes of the two 48 ON CERTAIN SURFACES parabolas being at right angles, their axes jmrallel, and theirconcavities turned in the same direction. Take the plane of the fixed parabola as j^lane of xy, its ivertex as origin, and its axis as axis of x. Then the plane ofthe moving… … axis of the moving parabola in 31, and draw QH and MNparallel to the axis of y. Then from the parabola PQ, P3P = z = r. QM, and from the parabola QO, QH = f = 1. OH =lx-l. QM . / ^_ OF THE SECOND ORDER. 49 40. The Hyperbolic Paraboloid. This is generated in the same manner as the last sur-face…
