Three vectors a→, b→ and c→ satisfy the relation a→.b→ = 0 and a→.c→ = 0.The vector a→ is parallel to
b→
c→
b→ .c→
b→ ×c→
a→.b→ = 0 i.e., a→ and b→ will be perpendicular to each other.
a→.c→ = 0 i.e., a→ and c→ will be perpendicular to each other.
b→ ×c→ will be a vector perpendicular to both b→ and c→
So a→ is parallel to b→ ×c→