prove that the following vectors are perpendicular to each other:

2i-j+k & i-3j-5k

 =(2i-j+k).(i-3j-5k)

=(2*1)+(-1*-3)+(1*-5)

=2+3-5

=0

since A.B=0

THE TWO VECTORS ARE MUTUALLY PERPENDICULAR TO EACH OTHER...