Question

let a=(-1,0,1) ,b=(2,-1,1) ,c=(-1,1,-1). Find (i) a×(b-c) (ii) a×b-(a×c)​

Answer 1

Answer:

a=(-1,0,1), b=(2,-1,1), c=(-1,1,-1).

a×(b-c)=? & a×b-(a×c)=?.

a=-1, b=2, c=-1.

a×(b-c)=-1×(2-(-1)).

=-1×(2+1). (Because -×-=+).

=-1×3.

=3. (Because -×+=- & largest number is important).

a×b-(a×c)=-1×2-(-1×-1).

=2-1.

=1.

a=0, b=-1, c=1.

a×(b-c)=0×(-1-1).

=0×2.

=0.

a×b-(a×c)=0×-1-(0×1).

=0-0.

=0.

a=1, b=1, c=-1.

a×(b-c)=1×{1-(-1).

=1×(1+1).

=1×2.

=2.

a×b-(a×c)=1×1-(1×-1).

=1-(-1). (Because +×-=-).

=1+1.

=2.

I think this is your answer.