Ryabushko A.P. IDZ 2.2 option 18

№1.18. 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; d) check whether coplanar three vectors: a (9; -3; 1); b (3; -15; 21); c (1, -5, 7).
№2.18. The tops of the pyramids are located at points A (5, -4, 4); B (-4; -6; 5); C (3; 2; -7); D (6, 2, -9) .........
№3.18. Given three powers P (-5; 8; 4); Q (6, -7, 3); R (3, 1, -5); applied to point A (2, -4, 7). Calculate a) the work done by the resultant of these forces; when the point of its application, moving rectilinearly moves to a point B (0, 7, 4); b) the value of
the resultant moment of the forces about point B.