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After I got the determinant from a matrix this is what I was left with a cubic equation.

How can I work with this?

$-3k^3-k^2+5 = 0$

I have looked at various links and websites like this one

https://www.wikihow.com/Solve-a-Cubic-Equation

But nothing seems to work with this cubic.

Liam
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  • This polynomial is irreducible over $\mathbb Q[x]$ , so it cannot be factored into two polynomials with integer coefficients. – Peter May 08 '20 at 11:37
  • You can factor it only over the reals or the complex numbers. – Peter May 08 '20 at 11:40

1 Answers1

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You can try it in Wolfram Alpha.

https://www.wolframalpha.com/input/?i=%E2%88%923k%5E3+-k%5E2%2B5

This polynomial has a single real root which is approximately $1.0843$.

If I were you I would check my previous calculations.
Maybe you have a mistake there and that's why you get this
particular polynomial and not some "nicer" one.

peter.petrov
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