# Find\_zero with Brent method

**URL:** <https://discourse.julialang.org/t/find-zero-with-brent-method/51569>\
**Category:** General Usage\
**Tags:** question\
**Created:** [December 9, 2020, 10:27pm UTC](https://discourse.julialang.org/t/find-zero-with-brent-method/51569 "2020-12-09T22:27:08Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![Yifan\_Liu](https://avatars.discourse-cdn.com/v4/letter/y/4da419/32.png) [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Post date:** [December 9, 2020, 10:27pm UTC](https://discourse.julialang.org/t/find-zero-with-brent-method/51569/1 "2020-12-09T22:27:08Z")

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I am trying to find the root of a function f. After using Roots,  
find\_zero(f, (0, 1), Roots.Brent()) works, but find\_zero(f, (0, 1), Brent()) does not work (error message says Brent not defined). When I use the Bisection method, find\_zero(f, (0, 1), Bisection()) works. I am confused by this name space issue.

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**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [December 9, 2020, 11:27pm UTC](https://discourse.julialang.org/t/find-zero-with-brent-method/51569/2 "2020-12-09T23:27:59Z")

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Not an expert, but would guess that Brent needs to be exported in **Roots.jl** file:

```julia
export Bisection, FalsePosition, Brent

```

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**Author:** ![Yifan\_Liu](https://avatars.discourse-cdn.com/v4/letter/y/4da419/32.png) [@Yifan\_Liu](https://discourse.julialang.org/u/Yifan_Liu)\
**Post date:** [December 9, 2020, 11:29pm UTC](https://discourse.julialang.org/t/find-zero-with-brent-method/51569/3 "2020-12-09T23:29:19Z")

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yeah. I don’t understand why they did not export Brent.

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**Author:** ![rafael.guerra](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rafael.guerra/32/216610_2.png) [@rafael.guerra](https://discourse.julialang.org/u/rafael.guerra)\
**Post date:** [December 9, 2020, 11:33pm UTC](https://discourse.julialang.org/t/find-zero-with-brent-method/51569/4 "2020-12-09T23:33:43Z")

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They did not export WTI either…  
PS: could not resist a silly Oil&Gas joke 🙂