# Why does Julia require a . for broadcasting?

**URL:** <https://discourse.julialang.org/t/why-does-julia-require-a-for-broadcasting/61180>\
**Category:** Internals & Design\
**Created:** [May 15, 2021, 12:40am UTC](https://discourse.julialang.org/t/why-does-julia-require-a-for-broadcasting/61180 "2021-05-15T00:40:44Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![aramirezreyes](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/aramirezreyes/32/42573_2.png) [@aramirezreyes](https://discourse.julialang.org/u/aramirezreyes)\
**Post date:** [May 15, 2021, 12:52am UTC](https://discourse.julialang.org/t/why-does-julia-require-a-for-broadcasting/61180/3 "2021-05-15T00:52:41Z")

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There is a well defined function usually called “exponential” of a matrix. It is not equal generally to the exponential of each element of the matrix. You can see this:

```julia
julia> a = rand(10,10)
julia> exp(a) == exp.(a)
false

```

If `exp(a)` did the exponential of every element of the matrix, how would you express the matrix exponentiation? You would then have to define some `mat_exp` which would lose many of the advantages that multiple dispatch brings us.

Oh! @Satvik is a much faster typer!

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