The vertices of a triangle are

MATHEMATICS · Subjective · A Level · Mathematics · Vectors · Vectors

Problem

P(1,2,3)

Q(4,0,-1)

and

R(-2,1,5)

. (i) Find the vectors

\vec{PQ}

and

\vec{PR}

. (ii) Obtain a vector normal to the plane of the triangle by evaluating

\vec{PQ}\times\vec{PR}

. (iii) Hence determine the unit vector perpendicular to the plane

PQR