Option 26 DHS 2.2

DHS - 2.2
No. 1.26. 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 a (-3; 2; 7) will be coplanar; b (1; 0; -5); c (6; 4; -1)
No. 2.26. The vertices of the pyramid are at points A (4; 3; 1); B (2; 7; 5); C (–4; –2; 4); D (2; –3; –5) .......
№ 3.26. Three forces P are given (7; –6; 2); Q (–6; 2; –1); R (1; 6; 4); attached to point A (3; –6; 1). Calculate a) the work produced by the resultant of these forces; when the point of its application, moving straight, moves to the point B (6; –2; 7); b) the value of the moment of the resultant of these forces relative to point B.