DHS - 3.1
№1.5. Four points A1 are given (9; 5; 5); A2 (–3; 7; 1); A3 (5; 7; 8); A4 (6; 9; 2). Create equations: a) plane A1A2A3; b) straight A1A2; c) direct A4M; perpendicular to the A1A2A3 plane; d) straight A3N; parallel straight line A1A2; e) a plane passing through point A4; perpendicular to the straight A1A2. Calculate: e) the sine of the angle between the straight line A1A4 and the plane A1A2A3; g) cosine of the angle between the coordinate plane Ox and
A1A2A3 plane.
No. 2.5. Make an equation for the plane passing through the axis Ox and point A (2; 5; –1).
# 3.5. Compose parametric equations of the median of a triangle with vertices A (3; 6; –7); B (–5; 1; –4); C (0; 2; 3); drawn from the top of C.