is this a challenge problem or you want to know how to do it?
IF A,B,C,D AND P ARE DIFF REAL NO. SUCH THAT (A2+B2+C2)P2-2P(AB+BC+CD)+B2+C2+D2<=0 THEN A,B,C,D AREIN
A.P
G.P
H.P
NONE
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3 Answers
					
			Manish Shankar
					·2008-12-29 00:32:31
			
			
		(AP-B)2+(BP-C)2+(CP-D)2≤0
is true when
(AP-B)2+(BP-C)2+(CP-D)2=0
AP=B, BP=C, CP=D
so A, B, C, D are in GP

