A) \[2\sin \theta \]
B) \[2\cos \theta \]
C) \[2\sin \theta /2\]
D) \[2\cos \theta /2\]
Correct Answer: C
Solution :
\[|\vec{a}|\,=1\]and \[|\vec{b}|\,=1\]or \[|\vec{a}-\vec{b}{{|}^{2}}=|\vec{a}{{|}^{2}}\]\[+|\vec{b}{{|}^{2}}=2\vec{a}\,\vec{b}\]\[=1+1-2\vec{a}\,\vec{b}=2-2|\vec{a}|\vec{b}|cos\theta \] \[\Rightarrow \]\[2-2{{\sin }^{2}}\theta /2=2\sin \theta /2\]
You need to login to perform this action.
You will be redirected in
3 sec
