Question

if cross product of vector P and vector Q is equal to zero vector and cross product of vector Q and vector R is equal to also zero vector then find the value of the cross product of the vector P and vector R

Answer 1

Cross product of two vectors is zero if , if the vectors are parallel.

Given that p×q = 0
=> p ll q

and..
q×r=0
=>

q ll r

as p llq and q ll r
=> p ll r
so p×r=0