,tex
so I found this question from a past test in the uni im gonna go to, it's supposedly a number theory problem, although that dont make much sense to me. anyways, here it is;
$$\int_{\mathcal{R}} \frac{5}{1 + x^2} \mathrm{d} x$$
#A problem from number theory(?)
dark stirrup
waxen tulipBOT
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dark stirrup
more of an integral than a question lol
$\int_{\mathbb{R}} \frac{5}{1 + x^2} \mathrm{d} x$
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dark stirrup
slight correction
dark stirrup
Use arctan
ohhh i thought so too, i just didnt know if that R makes it difficult
$\int_{-\infty}^{+\infty} \frac{5}{1 + x^2} \mathrm{d} x = 5 \arctan x from -\infty to +\infty$
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fast cape
ohhh i thought so too, i just didnt know if that R makes it difficult
```tex
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well you have to know the limits of arctan in the infinities, else you can also say that the function is even so the integral on R is 2 times the integral from 0 to +inf
but you still have to know arctan limits
dark stirrup
yepyep, i was confused because of the R in the lower limit, i'd never seen it written like that before
fast cape
if you all good you can type .close to close the forum
dark stirrup
.close