# Using "√" with a vector

**URL:** <https://discourse.julialang.org/t/using-with-a-vector/6025>\
**Category:** General Usage\
**Created:** [September 21, 2017, 2:57pm UTC](https://discourse.julialang.org/t/using-with-a-vector/6025 "2017-09-21T14:57:53Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![mbauman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/mbauman/32/31082_2.png) [@mbauman](https://discourse.julialang.org/u/mbauman)\
**Post date:** [September 21, 2017, 3:44pm UTC](https://discourse.julialang.org/t/using-with-a-vector/6025/3 "2017-09-21T15:44:20Z")

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The `√` is actually a prefix operator (and not just a function name) so you can do things like `√2`. This means that it gets dotted like all the other operators — with a dot prefix.

```julia
julia> .√[1,2,3]
3-element Array{Float64,1}:
 1.0
 1.41421
 1.73205

julia> .![true,false,true]
3-element BitArray{1}:
 false
  true
 false

julia> .-[1,2,3]
3-element Array{Int64,1}:
 -1
 -2
 -3

```

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