Question

find the angle between the vectors a=i+j-k and b=i-j+k

Answer 1

cos theata = 1×1+1×-1+(-1) ×1 upon root (1) square +(1) square +(-1) square ×root (1) square+(-1) square+(1) square

cos theta= 1-1-1 upon root 3× root

cos theta = -1/3

theta = cos inverse (-1/3)