The points P(a,b+c),Q(b,c+a) and R(c,a+b) are such that PQ=QR if(a≠b≠c)
a, b, c are in A.P
a, b, c are in G.P
a, b, c are in H.P
a, b, c are in A.G.P
PQ=QR⇒(b−a)2+(a−b)2=(c−b)2+(b−c)2
⇒(a−b)2=(b−c)2⇒a−b=b−c or a−b=c−b
i.e =a+c=2b or a=c