Question

if vector a=î-j+2k and b = 2i+j+k them what is the value of a.b​

Answer 1

Explanation:

a=i-j+k

b=2i+j+k

Now: by using cross product rule

a. b =|i j k|

1 -1 1 (the coefficients of i,j,&k respectively)

2 1 1

= i(-1-1) - j(1-2) +k(1+1)

= -2i +j +2k