Aldis, W. Steadman (William Steadman), 1839-1928 · Cambridge [Eng.] Deighton, Bell, and co.; London, G. Bell and sons · leaf 16
imilar to those of equation (2),o(, /3, 7 being the angles between PQ and the lines drawnthrough P parallel to the axes, viz. PH — x^ —x^ = PQ cos a = lr \ PM=y^ — y^ = PQ cos/5 = mr> (5), PL = ^2 ~ ^1 ^ ^Q ^^^ 7 = nr J where r represents the length of PQ, and I, 7n, n are the direction-cosines… … which divides PQ in the given ratio of n^ to n^. Let x^, y^, z^be the co-ordinates of P, ^2, y^, z^ those of Q, x, y\ z thoseof P. Draw Pil/, P//, QK parallel to the axis of z to meet theplane of xy in il/, Hy K. These points all lie in one straightline, namely that in which a plane through PQ…
