Ryabushko A.P. IDZ 2.2 option 20

DHS - 2.2
№ 1.20. Given the vector. It is necessary to: a) calculate the mixed product of three vectors; b) Find the unit vector product; c) to calculate the inner product of two vectors; g) check whether collinear or orthogonal two vectors; e) verify whether the three vectors are coplanar. a (-9; 4; -5); b (1, -2; 4); c (-5; 10; -20)
№2.20. The tops of the pyramids are located at points A (7; -1; -2); B (1, 7, 8); C (3; 7; 9); D (-3; -5; 2) ........
№3.20. Given three powers P (3, -4, 2); Q (2, 3, -5); R (-3; -2; 4); applied to point A (5; 3 -7). Calculate a) the work done by the resultant of these forces; when the point of its application, moving rectilinearly moves to point B (4; 1; to 4); b) the value of
the resultant moment of the forces about point B.