Answer :
the answer is
the vector PQ has (4-1, 8-2) as components, so it is vecPQ= (3, 6)
using the definition
the distance PQ= sqrt ( 3²+6²)= sqrt(9+36)=sqrt(45)
the vector PQ has (4-1, 8-2) as components, so it is vecPQ= (3, 6)
using the definition
the distance PQ= sqrt ( 3²+6²)= sqrt(9+36)=sqrt(45)