If P≡(1/xp,p);Q≡(1/xq,q);R≡(1/xr,r) where xk≠0,k=p,q,r belong to N,denotes the kth term of a harmonic progression,then
a.Area(ΔPQR)={(p2q2r2)/2}√((p-q)2+(q-r)2+(r-p)2)
b.ΔPQR is a right angled triangle
c.the points P,Q and R are collinear
d.none of these
If P≡(1/xp,p);Q≡(1/xq,q);R≡(1/xr,r) where xk≠0,k=p,q,r belong to N,denotes the kth term of a harmonic progression,then
a.Area(ΔPQR)={(p2q2r2)/2}√((p-q)2+(q-r)2+(r-p)2)
b.ΔPQR is a right angled triangle
c.the points P,Q and R are collinear
d.none of these










