Integration result: undefined

Luca Moroni shared this problem 11 months ago
Not a Problem

I've found this problem on twitter (original tweet by @mrdardy). Maybe a bug?


In Geogebra the command Integral(ℯ^x / ((ℯ^x)² + 1), 0, a) (where "a" is a slider) gives the correct result up to a=711.9198039 and becomes undefined beyond that value. Why? I know the integral should converge to pi/4 for a->inf.

Comments (5)

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I confirm

I think the integral should converge to pi/2 for a->inf.

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Am I wrong?d3ec8a28db87bf4ca2d316069106730d

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I've answered on twitter.

Calculate the integral using the Integral(function,x) command e.g. in row 1 of the CAS view, then evaluate it at infinity using Limit($1,infinity), as we usually do on paper. I agree with Luca on the result of the integral.

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I didn't read Zbynek's comment on Twitter before answering.

A more elegant solution is by using Integral((ℯ^x)/((ℯ^x)^2+1),0,Infinity) in CAS view of Classic ggb.

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I was clueless

I did from -inf to inf

the problem is "how I get the value from 0 to 1000. I think GG calculate exp(1000) first (there is an overflow) then atan()

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