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**Latkan** hey guys i gt tese two questions on dot and vectors , thing is im trying to revise and this topic is alien to me so hopefully by having several answers i can practice and understand....well thts the hope neways! :S

3.

(a) Define carefully the dot and vector products of two vectors a and b.

(b) Two unit vectors c and d are perpendicular. Find (c x d) . (2c + 3d).

(c) The three points. (-1, 2, 2), (2, 0, 1) and (1,2,1) form the vertices of a triangle. Use vector methods to find the angle between the two sides of the triangle which meet at (1, 2, 1). Find, also, using vector methods, the area of the triangle.

4.

(a) Define the dot and the cross product between two vectors a and b.

(b) Two unit vectors c and d are perpendicular. Find (c x d) x c.

(c) The three points (1, -2, 1), (0, 2, 1) and (-1, 1, 2) form the vertices of a triangle. Use vector methods to find the angle between the two sides of the triangle which meet at (0, 2, 1). Find, also, using vector methods, the area of the triangle.

Any help would be gratfully recieved thanks in advance