A) 0
B) -25
C) 25
D) none of these
Correct Answer: B
Solution :
\[\because \] \[|\vec{a}|=3,|\vec{b}|=5,|\vec{c}|=4\] and \[\vec{a}+\vec{b}+\vec{c}=0\] \[\therefore \] \[\vec{a}.\vec{b}+\vec{b}.b+\vec{c}.\vec{b}=\vec{0}\] \[\Rightarrow \]\[\vec{a}.\vec{b}+\vec{b}.\vec{c}=-|\vec{b}{{|}^{2}}\] \[\Rightarrow \]\[\vec{a}.\vec{b}+\vec{b}.\vec{c}=-25\]You need to login to perform this action.
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