7.`1/(p+q),1/(q+r),1/(r+p)` are in AP, then

If p, q. r in G.P and 1/(p-a),1/(r-p),1/(q-r) are in AP.show that p+4q+r=0

If P,Q,R are in A.P then Q-P=…..

If a_(1),a_(2),a_(3),…. are in A.P., then a_(p),a_(q),q_(r) are in A.P. if p,q,r are in

If a_(1),a_(2),a_(3),…. are in A.P., then a_(p),a_(q),q_(r) are in A.P. if p,q,r are in

If a ,1/b ,c and 1/p ,q ,1/r form two arithmetic progressions of the common difference, then a ,q ,c are in A.P. if p ,b ,r are in A.P. b. 1/p ,1/b ,1/r are in A.P. c. p ,b ,r are in G.P. d. none of these

If a_(1),a_(2),a_(3),…. are in A.P., then a_(p),a_(q),a_(r) are in A.P. if p,q,r are in

The vertices of a triangle are (p q ,1/(p q)),(q r ,1/(q r)), and (r p ,1/(r p)), where p ,q and r are the roots of the equation y^3-3y^2+6y+1=0 . The coordinates of its centroid are

If p,q,r are in G.P and tan^(-1)p,tan^(-1)q,tan^(-1)r are in A.P then p,q,r satisfies the relation

Let a(a != 0) is a fixed real number and (a-x)/(p x) = (a-y)/(qy) = (a-z)/(r z) . If p, q, r are in A.P., show that (1)/(x), (1)/(y), (1)/(z) are in A.P.