# Question about computing the determinant of matrix of indeterminate variables
**URL:** https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818
**Category:** Numerics
**Created:** [March 31, 2020, 7:59pm UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818 "2020-03-31T19:59:00Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Yusen\_Liu](https://discourse.julialang.org/u/Yusen_Liu)
#### Post date: [March 31, 2020, 7:59pm UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818/1 "2020-03-31T19:59:00Z")
Hi all, I’ve been struggling with computing the determinant of the matrix of indeterminate variables.
My code is as follows:
using TypedPolynomials
using LinearAlgebra
@polyvar p1 p2 p3 p4 p5 p6
A = [p1 p2 p3]
AT=transpose(A)
det(AT\*A)
I don’t know if there’s a way to compute the determinant since the result always shows 0.
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### Author:  [@saschatimme](https://discourse.julialang.org/u/saschatimme)
#### Post date: [March 31, 2020, 8:22pm UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818/2 "2020-03-31T20:22:14Z")
You compute the determinant of a rank 1 matrix which is always 0 🙂
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### Author:  [@Yusen\_Liu](https://discourse.julialang.org/u/Yusen_Liu)
#### Post date: [March 31, 2020, 8:33pm UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818/3 "2020-03-31T20:33:45Z")
Oh! Thanks!!
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### Author:  [@Tamas\_Papp](https://discourse.julialang.org/u/Tamas_Papp)
#### Post date: [April 1, 2020, 5:33am UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818/4 "2020-04-01T05:33:15Z")
Welcome to this forum! Also, please quote your code.
> [@PSA: how to quote code with backticks](https://discourse.julialang.org/t/psa-how-to-quote-code-with-backticks/7530):
>
> This is a short post on how to use backticks (` and ```) to quote code, so it is easy to read. This post can be linked to new users who are confused by this feature. Why By quoting your code, you get a monospaced font (which preserves indentation) and syntax highlighting. This makes it easier to read your code and help you. Displayed code looks like this: function displayed\_code(x::Int, y::Int) if x \< y println("x is smaller") else println("or not") end end Inline…
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### Author:  [@Yusen\_Liu](https://discourse.julialang.org/u/Yusen_Liu)
#### Post date: [April 6, 2020, 7:01am UTC](https://discourse.julialang.org/t/question-about-computing-the-determinant-of-matrix-of-indeterminate-variables/36818/5 "2020-04-06T07:01:45Z")
Thank you so much for reminding me of quoting the code.