If \bo {u}= {\a}- {\b}, \bo {v}= {\a}+ {\b}, and | {\a}|=| {\b}|=2, then | {\u} \times {\v}| is

Correct Answer is : 2√16−(a⋅b)2

2 \sqrt{16-( {\a} \cdot {\b})^2}