what is line and what is mean by direction cosine of the line and what does direction cosine reprsent??

Dear shamil Khan,

A line is a straight one-dimensional figure having no thickness and extending infinitely in both directions. A line is sometimes called a straight line or, more archaically, a right line , to emphasize that it has no "wiggles" anywhere along its length. 

Direction cosines are generallydenoted by l , m , n.If O be origin and P is a point whose co-ordinates are ( x , y , z ),then x = lr , y = mr , z = nr , where l , m , n are direction cosines of OP.

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Godfrey Classic Prince

IIT-M

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