Hi,

Is approximation the only way to solve Integral of e^(-x^2)/2 ?

What if the integral is indefinite? Any suggestions?

Thanks,

Max

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- Sep 3rd 2010, 08:39 AMMAX09Integration
Hi,

Is approximation the only way to solve Integral of e^(-x^2)/2 ?

What if the integral is indefinite? Any suggestions?

Thanks,

Max - Sep 3rd 2010, 09:37 AMwonderboy1953
I remember this integral being expressible in terms of pi.

- Sep 3rd 2010, 09:59 AMHallsofIvy
The definite integral from 0 to infintity or from negative infinity to infinity is "expressible in terms of ".

Whether "approximation the only way" depends upon what you mean by "approximation".

.

Would you consider only done by "approximation"? If not, how would you find arctan(x) for general x? - Sep 3rd 2010, 09:59 AMAllanCuz
You're thinking of the Gaussian integral: Gaussian integral - Wikipedia, the free encyclopedia

To answer the OP, if the bounds are from negative infinity to infinity then the integral will become . If, however, the bounds are finite the integral cannot be expressed in elementary functions: http://integrals.wolfram.com/index.jsp?expr=e^(-x^2)&random=false