In most calculus textbooks, they use double integrals to evaluate the Gaussian integral. Where did they get the idea - or how did they choose the two variable function [tex]e^{-(x^2+y^x)}[/tex] to evaluate it?(adsbygoogle = window.adsbygoogle || []).push({});

I guess this is related...but if you were given a fairly hairy integral and it was suggested that you write the integrand as an integral, how would you go about doing so? The example I have in mind is [tex]\int^2_0 arctan(\pi x)-arctan(x) dx[/tex]. The only way I know how to do that is by integration by parts

**Physics Forums | Science Articles, Homework Help, Discussion**

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Using double integrals to evaluate single integrals

**Physics Forums | Science Articles, Homework Help, Discussion**