# Symbolics.jl: Compute determinant

**URL:** <https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866>\
**Category:** Modelling & Simulations\
**Tags:** linearalgebra, symbolic, symbolics\
**Created:** [May 29, 2022, 1:05pm UTC](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866 "2022-05-29T13:05:44Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![DanDoe](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dandoe/32/52717_2.png) [@DanDoe](https://discourse.julialang.org/u/DanDoe)\
**Post date:** [May 29, 2022, 1:05pm UTC](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866/1 "2022-05-29T13:05:44Z")

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I would like to compute the determinant of a matrix involving a symbolic variable:

```julia
using Symbolics
I = # Identity matrix
A = # Some non-trivial matrix

@variables z

aux = I - z * A
det(aux)

```

[This webpage](https://juliasymbolics.org/) claims that computing determinants is possible, but I cannot find any documentation of that.

Does `Symbolics.jl` currently offer this feature, or do I have to resort to the `SymPy` wrapper for this?

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**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [May 29, 2022, 1:27pm UTC](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866/2 "2022-05-29T13:27:52Z")

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What’s the issue? It looks fine to me?

```julia
using Symbolics, LinearAlgebra
A = rand(2,2)

@variables z

aux = 1.0*I - z * A
det(aux) # (1.0 - 0.5011637014230891z)*(1.0 - 0.5128961372118938z) - 0.5815234891673762(z^2)

```

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<div class="post-metadata">

**Author:** ![stevengj](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stevengj/32/71_2.png) [@stevengj](https://discourse.julialang.org/u/stevengj)\
**Post date:** [May 29, 2022, 1:28pm UTC](https://discourse.julialang.org/t/symbolics-jl-compute-determinant/81866/3 "2022-05-29T13:28:35Z")

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> [@ChrisRackauckas](#):
>
> `using Symbolics, LinearAlgebra`

The key point is that the `det` function is exported by the `LinearAlgebra` package.