Q. 14.0( 6 Votes )

# Write the direction-cosines of the line joining the points (1, 0, 0) and (0, 1, 1). **[CBSE 2011]**

**[CBSE 2011]**

Answer :

Assuming the points to be P and Q.

The line joining the points P(1,0,0) and Q(0,1,1) can be represented with a vector . the given points P and Q can be represented using position vectors

As

∴

We know that direction cosine of a vector is given as-

cos α = ; cos β = and cos γ =

∴ Direction cosine of or line joining the points (1, 0, 0) and (0, 1, 1) is –

cos α =

cos β =

and cos γ =

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