Q5 of 76 Page 467

Find the direction cosines of the sides of the triangle whose vertices are (3, 5, –4), (-1, 1, 2) and (–5, –5, –2).


The direction cosines of the two points passing through A(x1, y1, z1) and B(x2, y2, z2) is given by


(x2 – x1), (y2-y1), (z2-z1)


And the direction cosines of the line AB is


Where AB =



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