№1 Given four points A1 (3; 1; 4); A2 (–1; 6; 1); A3 (–1; 1; 6); A4 (0; 4; –1). Draw up the equations: a) plane A1A2A3; b) straight line A1A2; c) direct A4M; perpendicular to the plane A1A2A3; d) direct A3N; parallel line A1A2; e) the plane passing through point A4; perpendicular to the straight line A1A2; Calculate: e) the sine of the angle between the straight line A1A4 and the plane A1A2A3; g) the cosine of the angle between the Ohu coordinate plane and the A1A2A3 plane.

№2 Find the values ​​of the segments cut off on the coordinate axes by a plane passing through the point M (–2; 7; 3) parallel to the plane x –4y + 5z - 1 = 0.

№3 Prove the parallelism of the lines (x -1) / 6 = (y + 2) / 2 = z / (- 1) and x – 2y + 2z – 8 = 0; x + 6z – 6 = 0.