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Question : 15 of 90
Marks:
+1,
-0
Solution:
∵ and
be the vectors along the diagonals of a parallelogram having area
2√2.
∴‌∣×=2√2||||sin‌θ=4√2⇒∣sin‌θ=4√2....‌ (i) ‌‌ and ‌⋅|=|×∣||||cos‌θ=||||sin‌θ⇒tan‌θ=1 ∴θ=‌By (i)
=8Now
=2√2×)−2⇒⋅=−2||2=−128and
⋅=8|×|2+4||2⇒|c|2=8.32+4.64⇒||=16√2From (ii) and (iii)
||‌cos‌α=−128⇒cos‌α=‌α=‌
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