Factorise: (p2+q2−r2)2−4p2q2
(p2+q2−r2)2−4p2q2 =(p2+q2−r2)2−(2pq)2[∵(a2−b2=(a+b)(a−b)] =(p2+q2−r2+2pq)(p2+q2−r2−2pq) =(p2+q2+2pq−r2)(p2+q2−2pq−r2) =((p+q)2−r2)((p−q)2−r2) =((p+q−r)(p+q+r))((p−q+r)(p−q−r)) =(p+q−r)(p+q+r)(p−q−r)(p−q+r)
If P(Q−r)x2+Q(r−P)x+r(P−Q)=0 has equal roots then 2Q=(where P,Q,r ϵ R)
Question 6 Angles Q and R of a ΔPQR are 25∘ and 65∘. Write which of the following is true: (i) PQ2+QR2=RP2 (ii) PQ2+RP2=QR2 (iii) RP2+QR2=PQ2