11.* 1 point the sum of the squares of the direction cosines of any line is always (b) 3 (a) 4 (c) 2 (d)t o a ob o c o d 6. 1 point the points (1,1,0), (0,1,1),

11.* 1 point The sum of the squares of the direction cosines of any line is always (b) 3 (a) 4 (C) 2 (d)T O a Ob O C O d 6. 1 point The points (1,1,0), (0,1,1), (1,0,1) and (2/3,2/3,2/3 ) are (a) coplanar () the vertices of a parallelogram (b) non coplanar (d) None of these.