Question

Show that the angle between the two lines in which the plane
intersects the cone is . (4)
(b) Using projection show that the line passing through (-1, 8, 8) and (6, 2, 0) is
perpendicular to the line passing through (4, 2, 3) and (2, 1, 2). (2)
(c) At what point the origin must be shifted so that linear terms in the conicoid
vanish? Justify.