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Question : 118 of 150
Marks:
+1,
-0
Solution:
(a) We know, scalar triple product
[] =
.(×) = (a×b).c
Consider
[+ + +] =
(+).
(+)×(+) =
(+).
{(×) +
(×) +
(×) +
(×)} =
(+).
{(×) +
(×) +
(×)} (∵×=0) =
.(×) +
.(×) +
.(×) +
.(×) +
.(×) +
.(×) =
[] +
[] +
[] +
[] +
[a] +
[] (By definition of scalar triple product)
[] = 0,
[] = 0 and
[] = 0
=
[] +
[] = 2
[]
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