№1 Given four points A1 (3; 2; 5); A2 (4; 0; 6); A3 (2; 6; 5); A4 (6; 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 For what values ​​of n and A is the straight line x / 3 = (y-5) / n = (z + 5) / 6 perpendicular to the plane Ax + 2y-2z-7 = 0?

№3 Make an equation for the plane passing through the point M0 (2; 3; 3) parallel to two vectors a = (- 1; -3; 1); b = (4; 1; 6).