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9 votes
2 answers
2k views

Wolfram says sum diverges, but Mathematica gives a numerical value for infinite sum [closed]

Take this sum for example: $$\sum_{n=2}^\infty\frac1{\log(n!)}$$ Wolfram says that this does not converge by the comparison test. However, when I use Mathematica's ...
John Glenn's user avatar
8 votes
1 answer
370 views

Differing answers when comparing Wolfram Alpha and Mathematica v.10.2

Out of curiousity, please consider following expression: Sum[(-1)^(n + 1)/n, {n, 1, 100000}] When evaluated using Wolfram Alpha: Result: ...
e.doroskevic's user avatar
  • 5,989
3 votes
4 answers
432 views

Conditional Summations

I am not a math major, but for a networking class, I am taking I am required to do summations for probability. I know the logic but I don't know the mathematical theory to make this work. Using ...
Edward Domka's user avatar
2 votes
2 answers
538 views

How to calculate complicated expression in WolframAlpha

I need to evaluate the limit: $$\lim_{n\to\infty}\prod_{k=1}^\infty \left(1-\frac{n}{\left(\frac{n+\sqrt{n^2+4}}{2}\right)^k+\frac{n+\sqrt{n^2+4}}{2}}\right).$$ I could not type into WolframAlpha ...
bilgamish's user avatar
2 votes
1 answer
317 views

Some Wolfram|Alpha Features I can't achieve in Mathematica

I have noticed some features available on the site Wolfram|Alpha which I am not managing to replicate. Two examples which come to mind are the following. Given a function $f(x)$, I want to determine ...
Luke Collins's user avatar