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 a (-3; -1; -5) are coplanar; b (2; -4; 8); c (3; 7; -1)

No. 2 The vertices of the pyramid are located at points A (–8; 2; 7); B (3; –5; 9); C (2; 4; –6); D (4; 6; –5) ...

No. 3 Given three forces P (5; 5; –6); Q (7; –6; 6); R (–4; 3; 4); applied to point A (–9; 4; 7). Calculate a) the work produced by the resultant of these forces; when the point of its application, moving rectilinearly, moves to point B (8; –1; 7); b) the magnitude of the moment of the resultant of these forces relative to point B.