How should I integrate?
$\int_0^\infty e^{-x^{1/3}}dx$
I think this is a simple question for the experts. But a bit hard to tell Google what I want. So, thanks for your help! :)
And this looks terrifying to me.
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Hint: Try the change of variable $u=x^{\frac{1}{3}}$ (so $dx=3u^2du$).
Clement C.
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Incidentally, WolframAlpha is (IMO) more convenient to use. – Clement C. May 18 '13 at 00:23
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wow, haven't done these since Freshman college, U-substitution? thanks for the hint. Still trying to remember why we do that. – user13985 May 18 '13 at 00:24
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I was googling for that site, there it is! – user13985 May 18 '13 at 00:25
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What do you mean by "U- substitution"? The reason for doing a change of variables like this is simply "the bit in the exponent looks tricky, let's simplify it by defining it to just be something new, like $u$". – not all wrong May 18 '13 at 00:44
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wait, it's not u-sub? can you link to me where this technique is from? – user13985 May 18 '13 at 00:49
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@Sharkos, see this. – J. M. ain't a mathematician May 18 '13 at 05:42
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lol, I see. Thanks J. M. – not all wrong May 18 '13 at 08:59