# Thread: integral problem

1. ## integral problem

Is there any difficult integral problem (calculus) still not solved yet by mathematics science

2. ## Re: integral problem

I'm not sure what you mean by this. There are plenty of integrals that can be integrated but not in terms of elementary functions. So we define a new function! For example, "erf(x)" is defined as $\displaystyle \int_0^x e^{-t^2} dt$.