Mark the correct alternative in each of the following:

If in a Δ ABC, A ≡ (0, 0), B ≡ (3, 3, √3), C ≡ (–3, √3, 3), then the vector of magnitude units directed along AO, where O is the circumcentre of Δ ABC is



Slope of a line joining two points


Slope of AC




Slope of AB




Product of Slopes (AC AB) =


= -1


As the Product of Slopes (AC AB) = -1, so AC AB, ie.., CAB = 90°.


Circumcentre (O) of Triangle ABC = Mid-Point of BC


Mid-Point of BC =




Now,





Unit Vector



Vector along , whose magnitude is




Option (A) is the answer.

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