Tim Bradshaw <t...@tfeb.org> writes: > On 2010-10-13 13:21:29 +0100, BartC said: > >> My money would have been on 0.25, based on using 1.0 for a 360° >> circular angle. It seems far more attractive than using the >> arbitrary-looking 6.28... > > It may look arbitrary, but it isn't: it's about as non-arbitrary as it > is possible to be.
Consider a few formulae that kids learn at school. In radians, given an angle θ in a circle of radius r: * length of arc = rθ * area of sector = 1/2 r²θ * d/dx(sin x) = cos x * d/dx(cos x) = -sinx x Let's use 1 for the angle 2π. Then: * length of arc = 2πrθ * area of sector = πr²θ * d/dx(sin x) = 2πcos x * d/dx(cos x) = 2πsin x We've removed one π, but now π crops up in every formula! -- Arnaud -- http://mail.python.org/mailman/listinfo/python-list
