# What's going on with exp() and --math-mode=fast?

**URL:** <https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619>\
**Category:** General Usage\
**Tags:** fast-math\
**Created:** [July 14, 2021, 8:34am UTC](https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619 "2021-07-14T08:34:03Z")\
**Posts on this page:** 1\
**Showing post:** 7

<div class="post-metadata">

**Author:** ![giordano](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/giordano/32/2166_2.png) [@giordano](https://discourse.julialang.org/u/giordano)\
**Post date:** [July 14, 2021, 1:34pm UTC](https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619/7 "2021-07-14T13:34:42Z")

</div>

> [@robsmith11](#):
>
> That seems unfortunate

I mean, the whole point of fast-math is trading off speed with correctness. If fast-math was to give always the correct results, it wouldn’t be fast-math, it would be the standard way of doing math.

---

_[View the full topic](https://discourse.julialang.org/t/whats-going-on-with-exp-and-math-mode-fast/64619)._