Question

If \( \vec{A}=2 \hat{i} \) and \( \vec{B}=-3 \hat{i}+\hat{j}-\sqrt{3} \hat{k} \) then magnitude of \( \vec{A} \times \vec{B} \) is (1) 13 (2) 5 (3) 4 (4) 6

Answer 1

AxB = 

Determinant

i	j	k
2	0	0
-3	-1	-sqrt(3)

AxB  = i(0) -j (-2sqrt(3)) + k ( -2 )

AxB  = j(2sqrt(3)) - 2k

|AxB|  = sqrt { 12 + 4 }  = 4