A) \[0\]
B) \[15\]
C) \[-15\]
D) \[15\sqrt{3}\]
Correct Answer: B
Solution :
We have magnitudes of \[\overrightarrow{OA}\]and \[\overrightarrow{OB}\] are 5 and respectively. And \[\angle BOA={{60}^{o}}\] Now, \[\overrightarrow{OA}.\overrightarrow{OB}=|\overrightarrow{OA}|.|\overrightarrow{OB}|.\cos \theta \] \[\Rightarrow \] \[\overrightarrow{OA}.\overrightarrow{OB}=5.6.\cos {{60}^{o}}\] \[\Rightarrow \] \[\overrightarrow{OA}.\overrightarrow{OB}=30\times \frac{1}{2}\] \[\Rightarrow \] \[\overrightarrow{OA}.\overrightarrow{OB}=15\]
You need to login to perform this action.
You will be redirected in
3 sec
