Number 1 are given the vector. It is necessary: ​​a) to calculate the mixed product of three three vectors; b) find the module of the vector product; c) calculate the scalar product of two vectors; d) check whether the two are collinear or orthogonal
vectors; e) check whether the three vectors are coplanar. a (-1; 0; 5); b (-3; 2; 2); c (-2; -4; 1).

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

No. 3 Force F (6; 5; –7) is applied to point A (7; –6; 4). Calculate a) the work of force in the case; when is the point of her application; moving in a straight line; moves to point B (4; 9; –6); b) the modulus of the moment of force with respect to point B.