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 three vectors will be coplanar: a (6; -4; 6); b (9; -6; 9); c (1; 0; -8).

No. 2 The vertices of the pyramid are located at points A (–5; –4; –3); B (7; 3; –1); C (6; –2; 0); D (3; 2; –7).

No. 3 Force F (–5; 4; 4) is applied to point A (3; 7; –5). Calculate a) the work of force F in the case; when is the point of her application; moving in a straight line; moves to point B (2; –4; 1); b) the modulus of the moment of force F relative to point B.