Question

if the angle between the vectors a and vector b is theta the value of the product of brexit b vector into a vector bracket close . a vector is equal to

Answer 1

let BxA = R

BxA is a vector which is perpendicular to both B & A ...

(BxA).A = R.A


R perpendicular to A so dot product will be 0 ...        

   (dot product of any two perpendicular vectors is 0)

so , (BxA).A =0

Answer 2

Hello dear,

● Answer -
(a×b).a = 0

● Explaination -
Consider θ be the angle between vector a & vector b.

Let's find out (a×b).a
(a×b).a = (a.a)×(b.a)
(a×b).a = (0)×(b.a)
(a×b).a = 0

Therefore, value of (a×b).a is 0.


# Important concepts used here -
1) Dot product of vector with itself is zero.
a.a = 0
2) Cross product of any vector with zero vector becomes zero.
0×r = 0


Hope this helps you clear concepts.
Thanks for the question.