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Question : 116 of 150
Marks:
+1,
-0
Solution:
=,= &
=are unit vectors and equally inclined to each other at an acute angle θ.
∴ ABC is an equilateral triangle
and
AB=√OA2+OB2−2OA⋅OB⋅cos‌θ
=√2−2‌cos‌θ=√2√1−cos‌θ∴ Area of ΔABC
If G is the centroid of the D ABC, then
OG=‌‌|++|=‌‌√1+2‌cos‌θ∴=Volume of parallelopiped
=OG×2ar(∆ABC)=(1−cos‌θ)√1+2‌cos‌θ
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