Вариант 28 ИДЗ 2.2

DHS - 2.2
№ 1.28. Given the vector. It is necessary: ​​a) to calculate the mixed product of the three vectors; b) find the module of the vector product; c) calculate the scalar product of two vectors; d) check whether the two vectors are collinear or orthogonal; e) check whether the three vectors a (4; -5; -4) will be coplanar; b (5; -1; 0); c (2; 4; -3);
No. 2.28. The vertices of the pyramid are at points A (3; 5; 3); B (–3; 2; 8); C (–3; –2; 6); D (7; 8; –2). .......
№ 3.28. Three forces P are given (7; 3; –4); Q (3; –2; 2); R (–5; 4; 3); attached to point A (–5; 0; 4). Calculate a) the work produced by the resultant of these forces; when the point of its application, moving in a straight line, moves to point B (4; –3; 5); b) size
the moment of the resultant of these forces relative to point B.