Show that the points (2, 3, 4), (– 1, – 2, 1), (5, 8, 7) are collinear 5 Find the direction cosines of the sides of the triangle whose vertices are
(3, 5, – 4), (– 1, 1, 2) and (– 5, – 5, – 2) © NCERT
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 MATHEMATI CS
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