Hi Marco, tnx for Your suggestion, it works. However this is not the only problem. I needed the output in this form: 1/(2^0)+1/(2^1)+1/(2/2)+...+1/(2^n) Is there some costruct either in Wa or in Mathematica that gives me the answer in that form? Tnx :-) Eugenio

Here is my question: I have to calculate the definite integral from 0 to 1 of a series sum from n= 1 to infinity. The function is ((n+2)/(2^n))x^(n+1) I've tried to use this syntax in WA search engine:

I am not too familiar with the Wolfram Alpha language syntax. I only use the Wolfram Mathematica language, and the syntax in that language is

f = ((n + 2)/(2^n)) x^(n + 1);
fi = Integrate[f, {x, 0, 1}];
Sum[fi, {n, 1, Infinity}]

And the answer is 1. May be the above will help you translate that to the Wolfram Alpha syntax more easily now. Wolfram Alpha should also accept Wolfram Mathematica syntax as far as I know. So the above should works as is inside Wolfram Alpha but I have not tried it.