1. 10
  1. 11
    1. 3

      Thanks, I added a reference at the end of the post!

    2. 2

      Fascinatingly (to me) the author of this article took nearly exactly the same journey I recently (I guess not so recent.. time flies) took when trying to solve the same problem. My version is here: https://dpzmick.com/posts/2021-03-28-polynomial-from-roots.html

      Turns out there’s also functions in numpy and co that perform a special case of this operation, like the clearly named zpk2tf. These essentially are just repeatedly convolving new terms into a poynomial until all terms are consumed.

      1. 1

        Fascinatingly (to me) the author of this article took nearly exactly the same journey I recently (I guess not so recent.. time flies) took when trying to solve the same problem. My version is here: https://dpzmick.com/posts/2021-03-28-polynomial-from-roots.html

        Oh, nice.

        Turns out there’s also functions in numpy and co that perform a special case of this operation, like the clearly named zpk2tf. These essentially are just repeatedly convolving new terms into a poynomial until all terms are consumed.

        Even with multiple characters available to name things, mathematicians can’t resist to use cryptic namings…

      2. 2

        I don’t believe I had heard of Vietas Formulas before today and now I’v heard about them in two unrelated contexts! They came up in a numberphile video about question 6 of the 1988 IMO https://youtu.be/NcaYEaVTA4g

        1. 1

          This is one of those super fascinating things about how mathematics is taught around the globe: I was taught this crap stuff in high school. I have no idea why but it was considered pretty important. To this day, I don’t think I’ve used this for anything other than scoring nerd points and solving high school algebra problems. I was in high school at a time when high school curricula was slowly being dragged into our age so there were a few odd relics, like a whole bunch of obscure tricks with logarithms that we didn’t quite know what to do with because the use of logarithm tables to simplify tedious multi-digit operations was no longer taught. I suspect this was one of those things.