Q.

If the points P and Q are respectively the circumcenter and the orthocentre of a ∆ABC, then PA→+PB→+PC→ is             [2023]

1 2PQ→  
2 QP→  
3 2QP→  
4 PQ→  

Ans.

(4)

PA→+PB→+PC→=a→+b→+c→

=3(a→+b→+c→)3

=3PG→=PQ→