(A)→(P,R,S),(B)→(P),(C)→(P,Q),(D)→(S,T)a2−b2=3c2(given)4R2(sin2X−sin2Y)=2sin2(Z)4R2⇒2(sin(X−Y)⋅sin(X+Y))=sin2(z)⇒2⋅sin(X−Y)⋅sin(Z)=sin2(Z)⇒sinZsin(X−Y)=21=λ⇒cos(2nπ)=0 for n=odd integer(B)1+cos2X−2cos2Y=2sinXsinYsin2X+sinXsinY−2sin2Y=0(sinX−sinY)(sinX+2sinY)=0⇒sinX=sinY⇒sinYsinX=ba=1
(C) Here,distance of Z from bisectors of OXandOY=23⇒(β−21)2+(β−21)2=29⇒β=2,-1⇒|β|=2,1(D)when α=0Area =6−∫022xdxdx=6−382when α=1