IIT JEE , AIEEE Forum - Mathematics , Algebra

rtiit

If there be n quantities in G.P., whose common ratio is r and Sm denotes sum of first m terms then sum of their products taken 2 by 2 is

rtiit

ne1 solve dis plz

pottermania1990

its a g.p with the first term as a^2r with common ratio r^2

apply the summatn formula..u can just rearrange to get the answ. in terms of sm.

im srry that i cant do the qn.fully..may b a lill later..

rtiit

can ne1 give the detailed solution plz m not gettin it

Decoder

can u tell me wat is this 2 by 2..??
is this two at a time..??
soln assured..

rtiit

ya it's two at a time......

Decoder

sum taken two at a time is S..

now S = { S_M + sum of individual squares of g.p..} / 2

now wat is this individual square sum..

actually it is a g.p with first term a² and common ratio r² ........

so tht sum is equal to..a² { a^2m - 1} / r² -1...

write this in term of S_M and get the ans..

rtiit

thank u very much

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