a simple one but I cant remember how to do this!!!
Find sum of the series...
Hello,
Let
Therefore :
is an arithmetic series of progression 3.
Hmmm, can you continue ?
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Here is another method :
You should know the general formula for .
And for , represent yourself adding 2, adding again, and again, and again..
(let's see first if you can do the first one ^^)
Edit : oh, well...topsquark spoiled it