more trig!

2017-Aug-29, Tuesday 09:38
mindstalk: (Default)
[personal profile] mindstalk
I forgot about the laws of sine and cosine. They're easy to prove once you know them, though I don't know about discovering them from scratch.

I was reminded after the previous post that you can get another triangle with just a fair bit of algebra. sin 2*18 = cos 3*18, solve for sin 18; you'll get a quadratic, and a fairly simple solution (-1+sqrt(5))/2. (If you try sin 18 = cos 4*18, you get a quartic, and I don't know how to solve it analytically.)

I've been writing code to approximate log or powers via iterated square roots. It works, though takes a fair number of steps.
From:
Anonymous (will be screened)
OpenID (will be screened if not validated)
Identity URL: 
User
Account name:
Password:
If you don't have an account you can create one now.
Subject:
HTML doesn't work in the subject.

Message:

 
Notice: This account is set to log the IP addresses of everyone who comments.
Links will be displayed as unclickable URLs to help prevent spam.

Most Popular Tags