1If A1,A2,........An are n arithmetic means between a and b , a,A1,A2....,An,b ARE IN A.P.
A1=(a + b-a/n+1) ,A2=(a + 2(b-a)/n+1)
An=(a + n(b-a)/n+1)
now, A1+An=A2+An-1=.......=a+b(try adding them)
4 Answers
1
1oh,sorry posted wrong question..............now i have changed it plz try now!!!
39http://targetiit.com/iit_jee_forum/posts/hp_2_9320.html
that should help u
1Since a,b,c,d are in H.P., 1/a,1/b,1/c,1/d are in A.P. 1/b - 1/a=1/c - 1/b=1/d -1/c=m then, a-b=mab ,b-c=mbc ,c-d=mcd ,1/d-1/a=3m a-d=3mad \Rightarrowa-d=m(ab+bc+cd) \Rightarrow3mad=m(ab+bc+cd)