If the angle between the vectors A and B is `theta`, the value of the product (BxA). A is equal to

Options

A. `BA^(2)costheta`
B. `BA^(2)sintheta`
C. `BA^(2)sinthetacostheta`
D. zero

Answer

D

Explanation

As `p*(qxxr)=|(p_(x),p_(y),p_(z)),(q_(x),q_(y),q_(z)),(r_(x),r_(y),r_(z))|`
=scalar triple product
`p*(qxxr)=q*(rxxp)=r*(pxxq)`
`=(qxxq)*r`
`=(qxxr)*p=(rxxp)*q`
Given triplee product is `(BxxA)*A`
Interchanging the cross and dot, we have
`(BxxA)*A=B*(AxxA)=0`
`(becauseAxxA=0)`