Number 1 are given the vector. It is necessary: ​​a) to calculate the mixed product of three vectors; b) find the module of the vector product; c) calculate the scalar product of two vectors; d) check whether two vectors are collinear or orthogonal; e) check whether the three vectors are coplanar. a (3; -1; 2); b (-1; 5; -4); c (6; -2; 4).

No. 2 The tops of the pyramid are located at points A (7; 4; 2); B (–5; 3; –9); C (1; –5; 3); D (7; –9; 1) ...

No. 3 Given three forces P (6; –4; 5); Q (–4; 7; 8); R (5; 1; –3); applied to point A (–5; –4; 2). Calculate a) the work produced by the resultant of these forces; when the point of its application, moving rectilinearly, moves to point B (7; –3; 6); b) the value
the moment of the resultant of these forces with respect to point B.