№1.13. Given the vector. It is necessary: ​​a) to calculate the mixed product of the three vectors; b) find the module of the vector product; c) calculate the scalar product of two vectors; d) check whether the two vectors are collinear or orthogonal; e) check whether the three vectors are coplanar: a (-5; 2; -2); b (7; 0; -5); c (2; 3; -2).
№2.13. The vertices of the pyramid are at points A (–4; –7; –3); B (–4; –5; 7); C (2; –3; 3); D (3; 2; 1) .......
No. 3.13. Three forces are given Q (9; –3; 4); P (5; 6; –2); R (–4; –2; 7); attached to point A (–5; 4; –2). Calculate a) the work produced by the resultant of these forces; when the point of its application, moving in a straight line, moves to point B (4; 6; –5); b) the magnitude of the moment of the resultant of these forces relative to point B.