Question
Question: vectors <img src="https://cdn.pureessence.tech/canvas_66.png?top_left_x=0&top_left_y=1143&width=300&...
vectors
and
with magnitude 2, 3 & 4 respectively are coplanar. A unit vector
is perpendicular to all of them. If (a×b)×(c×d)
=6i^−3j^+3k^ and the angle between a and b is 300, then
is equal to
A
35
B
95
C
125
D
185
Answer
185
Explanation
Solution
= ∣a∣ ∣b∣ sin 300 n^ = 
since
is perpendicular to a&b Ž
= ± 
\
= ± 3
Now (a×b)×(c×d)= ± 
Ž ± 3
Or ±
Ž
,
, 
