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Two lines with direction cosines l(1),m(...

Two lines with direction cosines `l_(1),m_(1),n_(1) and l_(2), m_(2), n_(2)` are at right angle of

A

`l_(1)l_(2)-m_(1)m_(2)-n_(1)n_(2)=0`

B

`l_(1)l_(2)+m_(1)m_(2)+n_(1)n_(2)=0`

C

`l_(2)=l_(2), m_(1)=m_(2),n_(1)=n_(2)`

D

`(l_(1))/(l_(2))=(m_(1))/(m_(2))=(n_(1))/(n_(2))`

Text Solution

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The correct Answer is:
B
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