Number 1 are given the vector. It is necessary: ​​a) to calculate the mixed product of three vectors; b) find the modulus 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; 2; 7) are coplanar; b (1; 0; -5); c (6; 4; -1)

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

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