A) 2
B) 3/2
C) ½
D) 1
Correct Answer: C
Solution :
[c] \[\left| {{{\bar{a}}}_{1}}+{{{\bar{a}}}_{2}} \right|=\sqrt{a_{1}^{2}+a_{2}^{2}+2{{a}_{1}}{{a}_{2}}\cos \theta }=\sqrt{3}\] \[\Rightarrow \] \[\cos \theta =\frac{1}{2}\] \[({{\bar{a}}_{1}}-{{\bar{a}}_{2}})(2{{\bar{a}}_{1}}+{{\bar{a}}_{2}})=2a_{1}^{2}-a_{2}^{2}-{{a}_{1}}{{a}_{2}}\cos \theta =\frac{1}{2}\]You need to login to perform this action.
You will be redirected in
3 sec