Mathematics Part-II

Book: Mathematics Part-II

Chapter: 10. Vector Algebra

Subject: Maths - Class 12th

Q. No. 11 of Miscellaneous Exercise

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Show that the direction cosines of a vector equally inclined to the axes OX, OY and OZ are


let the vector equally inclined to OX, OY and OZ at angle α.

Then the direction cosine of the vectors are cos α, cos α and cos α.


Cos2α + Cos2α + Cos2α = 1

3 Cos2α = 1

Cos2α = 1/3

Hence, the direction cosines of the vector which are equally inclined to the axis are



Chapter Exercises

More Exercise Questions


If , then is it true that ? Justify your answer.