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Quiz: calculating a definite integral
01-07-2014, 06:12 PM
Post: #45
RE: Quiz: calculating a definite integral
(01-06-2014 10:28 AM)Thomas Klemm Wrote:  
(01-03-2014 09:04 PM)Bunuel66 Wrote:  Don't get the point, \(\exp(-\infty)\)=0.

The domain of \(\exp(x)\) is \(\mathbb{R}\), but \(-\infty \notin \mathbb{R}\). Thus you can not just plug \(-\infty\) into the Taylor-series of this function and expect everything works. You can calculate \(\lim_{x\to\infty}\exp(x)\) but that's not the same as \(\exp(-\infty)\). This expression is just not defined.

HTH
Thomas

Could have been rewriten as a limit to be more rigorous...;-) That said the serie gives the same value than the function also for x<0. Doesn't seems to be the point. And as you mention this is not a Taylor serie strictly speaking.

Regards.
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RE: Quiz: calculating a definite integral - Bunuel66 - 01-07-2014 06:12 PM



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