Given (pq−qr+pr)(pq+qr)−(pr+pq)(p+q−r)=pq(pq+qr)−qr(pq+qr)+pr(pq+qr)−pr(p+q−r)−pq(p+q−r)=[p2q2+pq2r−pq2r−q2r2+p2qr+pqr2]−[p2r+pqr−pr2+p2q+pq2−pqr]=p2q2+pq2r−pq2r−q2r2+p2qr+pqr2−p2r−pqr+pr2−p2q−pq2+pqr=p2q2−q2r2+p2qr+pqr2−p2r+pr2−p2q−pq2
Question 9
In ΔPQR,
a) PQ - QR > PR b) PQ + QR < PR c) PQ - QR < PR d) PQ + PR < QR