Integral

[old folio]

take u =x/ root(2)sigma

@real relic

[real relic]

ill give it a go, thanks

ive done the u sub, what do i do after that?

the only thing i can think of is by parts but i think we want it in terms of the second int

[old folio]

don’t you know that the integral of e^-u^2 is root(pi)

[rapid pasture]

Hi, you can do it by directly integrating by parts

Then you'll have to use the given integral

[real relic]

wouldnt u have to do u sub aswell?

[rapid pasture]

Not as your first step

You can use it elsewhere

[real relic]

cuz we have to integrate e^-x^2/2sigma

[rapid pasture]

Can you show what you did?

[real relic]

im not too sure how to go on, i havent gotten to the point of integrating e^x^2 yet

oh wait its the gaussian integral

[rapid pasture]

I can't really follow your u-subs

What is the first thing you did

[real relic]

for int by parts, i made u = x^2

the top right part should be crossed out

[rapid pasture]

You have a small problem then

You will have to calculate the anti-derivative of exp(-x^2/2 σ^2)

And that doesn't exist

[real relic]

how did u do it?

[rapid pasture]

take $u = x e^{\frac{-x^2}{2\sigma^2}}$

[cedar cedar]

zlik

[rapid pasture]

oh that's wrong

it should be

$u = x$

[cedar cedar]

zlik

[rapid pasture]

does that work?

[real relic]

I dont know where to go from here

[rapid pasture]

okay, so for the left term you have to calculate two limits

and for the integral, you can look at the given one

[real relic]

can i apply the terms to the integral?

[rapid pasture]

Also be aware when writing the boundaries of the integral like that, I don't know if it's correct that way

[rapid pasture]

what do you mean?

[real relic]

thats how ive always done it, maybe its slightly different cuz im in the UK

yeah i got it, sigma^2

thanks a bunch

[rapid pasture]

if you're teacher is ok with it, it's fine

[rapid pasture]

that's correct

[rapid pasture]

no worries

[old folio]

yes bro 😂😂😂

that’s why i told you to do that u substitution

[rapid pasture]

I don't know if you two know eachother but if not,
why are you so condescending? Everybody is on a different level in their education.

[real relic]

Tbh I only started doing integration 6 months ago lol

[real relic]

Fair 🤣

[old folio]

he’s my best friend

[warped idol]

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