№ 1.28. Four points A1 are given (2; 1; 7); A2 (3; 3; 6); A3 (2; –3; 9); A4 (1; 2; 5). Create equations: a) plane A1A2A3; b) straight A1A2; c) straight A4M, perpendicular to the A1A2A3 plane; d) straight A3N parallel to straight line A1A2; e) a plane passing through the point A4, perpendicular to the straight line A1A2. Calculate: e) the sine of the angle between the straight A1A4 and the plane A1A2A3; g) the cosine of the angle between the coordinate plane Oxu and the plane A1A2A3.
No. 2.28. Create an equation for the plane passing through the origin perpendicular to the planes x + 5y - z + 7 = 0 and
3x - y + 2z - 3 = 0.
№ 3.28. Make an equation of a straight line passing through the point M (2; 3; 1) perpendicular to the line .....