1. ## Fun easy integral

This is reallyl easy if you see it

$\int_{\frac{-\pi}{2}}^{\frac{\pi}{2}}\bigg[\int\bigg[\int\bigg[\int{e^{-x^2}dx}\bigg]dx\bigg]dx\bigg]dx$

2. Originally Posted by Mathstud28
This is reallyl easy if you see it

$\int_{\frac{-\pi}{2}}^{\frac{\pi}{2}}\bigg[\int\bigg[\int\bigg[\int{e^{-x^2}dx}\bigg]dx\bigg]dx\bigg]dx$
Oh and you should put a numerical answer

Big hint^

3. Originally Posted by Mathstud28
This is reallyl easy if you see it

$\int_{\frac{-\pi}{2}}^{\frac{\pi}{2}}\bigg[\int\bigg[\int\bigg[\int{e^{-x^2}dx}\bigg]dx\bigg]dx\bigg]dx$
Come on...no one can do this?

4. ## Just a guess

Well I don't see it but I've done a similar integral once and the answer was 0 due to that the integrated function was odd and the bounds of the integral were opposed in signs. I'd like to "see" what you see... so if it's not too much asked, message me in private so others can do your integral.

5. Originally Posted by arbolis
Well I don't see it but I've done a similar integral once and the answer was 0 due to that the integrated function was odd and the bounds of the integral were opposed in signs. I'd like to "see" what you see... so if it's not too much asked, message me in private so others can do your integral.
I think you got it, I'm fairly sure that Mathstud28 expect some approach using an infinite series. I believe you need to use Taylors theorem to show that $e^{-x^2}$ can be express as a polynomial which only have even powers of x in the series. Then integrating term by term three times yields you with an polynomial with only odd power of x, hence and odd function, so the integral would be zero within those limits.

also Mathstud28 don't bump your thread constantly, its actually against the site rules.

Bobak

6. Originally Posted by bobak
I think you got it, I'm fairly sure that Mathstud28 expect some approach using an infinite series. I believe you need to use Taylors theorem to show that $e^{-x^2}$ can be express as a polynomial which only have even powers of x in the series. Then integrating term by term three times yields you with an polynomial with only odd power of x, hence and odd function, so the integral would be zero within those limits.

also Mathstud28 don't bump your thread constantly, its actually against the site rules.

Bobak
Yes you were both correct...I didnt need someone to show the erf(x) I just wanted it known that erf(x) is odd

7. "I just wanted it known that erf(x) is odd". You succeed with me... Since I almost never studied this function I didn't know that it was odd. Anyway, I believe that it wasn't that easy to see that the integral was equal to 0... If you have never done a similar exercise, then it's quite hard.

8. Originally Posted by arbolis
"I just wanted it known that erf(x) is odd". You succeed with me... Since I almost never studied this function I didn't know that it was odd. Anyway, I believe that it wasn't that easy to see that the integral was equal to 0... If you have never done a similar exercise, then it's quite hard.
I dont know...maybe you are right...it seemed obvious to me...but maybe that is because I made it up haha

9. Nice one, and yes it explains all.