№1 Given four points A1 (1; –1; 3); A2 (6; 5; 8); A3 (3; 5; 8); A4 (8; 4; 1). Draw up the equations: a) plane A1A2A3; b) straight line A1A2; c) a straight line A4M perpendicular to the plane A1A2A3; d) line A3N parallel to line A1A2; d) a plane passing through point A4, perpendicular to the 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;

No. 2 Make the equation of the plane; passing through the axis Oy and point M (3; –5; 2).

№3 At what value of D is the line .... intersecting the Oz axis?