Skip to main content
5 events
when toggle format what by license comment
Jan 27, 2012 at 13:57 vote accept bobuhito
Jan 24, 2012 at 10:11 vote accept bobuhito
Jan 25, 2012 at 10:03
Jan 21, 2012 at 23:47 comment added Noam D. Elkies This works; still, it's easier to get from "Heronian triangle with side-lengths $a,ra,b$" to "rational point on $y^2 = x(x-1)(x-r^2)$" using Heron's formula than using the formulas for $\sin A$ and $\cos A$ (granted that these formulas are one approach to Heron's formula too).
Jan 21, 2012 at 18:48 comment added bobuhito Thanks! But, can you elaborate on "Testing gives the rank equal to 0"? My impression is that there is no general way to determine the rank but sometimes "infinite descent" luckily shows it's zero. So, if you need to be specific, can you show why 1/3 gives zero, and what the rank of a more random ratio like 6/17 is?
Jan 20, 2012 at 20:48 history answered Allan MacLeod CC BY-SA 3.0