4 ms·

Here is a "Proof of the Law of Cosines" by the same author: https://www.tandfonline.com/doi/pdf/10.4169/amer.math.monthly.121.02.149 https://www.tandfonline.co

Here is a "Proof of the Law of Cosines" by the same author: https://www.tandfonline.com/doi/pdf/10.4169/amer.math.monthly.121.02.149 https://www.tandfonline.com/doi/pdf/10.4169/amer.math.monthl... But this time not with complex numbers.

mehulashah 2y ago
So, I have to pay to read the proof? Not fun.
- milesde 2y ago
  It's also on JSTOR: https://www.jstor.org/stable/10.4169/amer.math.monthly.121.02.149 https://www.jstor.org/stable/10.4169/amer.math.monthly.121.0... . No payment needed there (unless you've burned through your 100 free articles for this month).
  - ColinWright 2y ago
    I appreciate that, but it requires creating an account, and for people who have a gazillion other things to be doing, taking the time to create Yet Another Account on Yet Another System just for the one article is something most people will pass on. It may not have a financial cost, but it certainly has an opportunity cost, and contributes to "Account Fatigue". But loved the proof of Heron's formula, and I'm pleased to be able to say thank you in person, and make sure I give credit when I use it for the Math Club talks I do. Great work ... feel free to contact me if you are so inclined, or put an email address in your profile.