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If the direction cosines of two lines ar...


If the direction cosines of two lines are `(l_(1), m_(1), n_(1))` and
`(l_(2), m_(2), n_(2))` and the angle between them is `theta` then
`l_(1)^(2)+m_(1)^(2)+n_(1)^(2)=1=l_(2)^(2)+m_(2)^(2)+n_(2)^(2)`
and costheta` = l_(1)l_(2)+m_(1)m_(2)+n_(1)n_(2)`
If `l_(1)=1/sqrt(3), m_(1)=1/sqrt(3)` then the value of `n_(1)` is equal to

A

`pm 1/sqrt(3)`

B

`+ 1/sqrt(3)`

C

` -1/sqrt(3)`

D

0

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The correct Answer is:
A
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